Journal articles: 'Lc-hrms'

1

Katahira, Takehiro, Akio Kanazawa, Mai Shinohara, et al. "Postprandial Plasma Glucagon Kinetics in Type 2 Diabetes Mellitus: Comparison of Immunoassay and Mass Spectrometry." Journal of the Endocrine Society 3, no. 1 (2018): 42–51. http://dx.doi.org/10.1210/js.2018-00142.

Full text

Abstract:

Abstract Context Accurate glucagon level measurements are necessary for investigation of mechanisms for postprandial hyperglycemia in type 2 diabetes. Objective To evaluate the accuracy of postprandial glucagon level measurements using a sandwich ELISA vs a recently established liquid chromatography-high resolution mass spectrometry (LC-HRMS) method in type 2 diabetes mellitus. Design and Participants Twenty patients with type 2 diabetes treated with insulin underwent a meal test before and after administration of the dipeptidyl peptidase-4 inhibitor anagliptin for 4 weeks. Blood samples were taken serially after the meal, and glucagon levels were measured using both ELISA and LC-HRMS. We compared the change from baseline to 4 weeks (Δ0–4W) using the area under the curve for plasma glucagon during the meal test [area under the curve (AUC)0–3h] measured using ELISA and LC-HRMS. Results ELISA-based glucagon AUC0–3h was higher than LC-HRMS–based AUC0–3h at baseline and 4 weeks. However, differences in Δ0–4W-AUC0–3h measured using ELISA and LC-HRMS were not statistically significant. Additionally, Δ0–4W-AUC0–3h measured using ELISA and LC-HRMS were strongly correlated (r = 0.87, P &lt; 0.001). Conclusions Plasma glucagon levels during a meal test in patients with type 2 diabetes measured using ELISA were consistently higher than those measured using LC-HRMS. However, given that the changes in glucagon levels measured using ELISA before and after dipeptidyl peptidase-4 inhibitor therapy were similar to those based on LC-HRMS, this ELISA seems to be useful for evaluating the effect of the drug interventions on postprandial glucagon levels.

APA, Harvard, Vancouver, ISO, and other styles

2

Sun, Yuchen, Shin-ichiro Nitta, Kosuke Saito, et al. "Development of a bioanalytical method for an antisense therapeutic using high-resolution mass spectrometry." Bioanalysis 12, no. 24 (2020): 1739–56. http://dx.doi.org/10.4155/bio-2020-0225.

Full text

Abstract:

Background: Ion-pairing reverse-phase LC coupled with high-resolution mass spectrometry (IP-LC/HRMS) has gained attention in oligonucleotide therapeutic bioanalyses owing to its high sensitivity and selectivity. However, optimization and validation of IP-LC/HRMS-based methods are rare. The objective of this study is the development of a sensitive and reproducible IP-LC/HRMS-based bioanalytical method using clinically approved mipomersen as a model for antisense oligonucleotides. Materials & methods/results: Mipomersen was extracted from rat plasma using Clarity OTX SPE and quantified by IP-LC/HRMS. The calibration range was 0.5–250.0 ng/ml. The developed method met the general regulatory criteria for accuracy, precision, carry-over, selectivity, matrix effect and dilution integrity. Conclusion: A highly sensitive and reliable method for mipomersen measurement with potential antisense oligonucleotide bioanalysis applications has been developed.

APA, Harvard, Vancouver, ISO, and other styles

3

Maldini, Mariateresa, Gilda D’Urso, Giordana Pagliuca, et al. "HPTLC-PCA Complementary to HRMS-PCA in the Case Study of Arbutus unedo Antioxidant Phenolic Profiling." Foods 8, no. 8 (2019): 294. http://dx.doi.org/10.3390/foods8080294.

Full text

Abstract:

A comparison between High-Performance Thin-Layer Chromatography (HPTLC) analysis and Liquid Chromatography High Resolution Mass Spectrometry (LC–HRMS), coupled with Principal Component Analysis (PCA) was carried out by performing a combined metabolomics study to discriminate Arbutus unedo (A. unedo) plants. For a rapid digital record of A. unedo extracts (leaves, yellow fruit, and red fruit collected in La Maddalena and Sassari, Sardinia), HPTLC was used. Data were then analysed by PCA with the results of the ability of this technique to discriminate samples. Similarly, extracts were acquired by non-targeted LC–HRMS followed by unsupervised PCA, and then by LC–HRMS (MS) to identify secondary metabolites involved in the differentiation of the samples. As a result, we demonstrated that HPTLC may be applied as a simple and reliable untargeted approach to rapidly discriminate extracts based on tissues and/or geographical origins, while LC–HRMS could be used to identify which metabolites are able to discriminate samples.

APA, Harvard, Vancouver, ISO, and other styles

4

Lefebvre, Donatien, Kevin Blanco-Valle, Jacques-Antoine Hennekinne, et al. "Multiplex Detection of 24 Staphylococcal Enterotoxins in Culture Supernatant Using Liquid Chromatography Coupled to High-Resolution Mass Spectrometry." Toxins 14, no. 4 (2022): 249. http://dx.doi.org/10.3390/toxins14040249.

Full text

Abstract:

Staphylococcal food poisoning outbreaks are caused by the ingestion of food contaminated with staphylococcal enterotoxins (SEs). Among the 27 SEs described in the literature to date, only a few can be detected using immuno-enzymatic-based methods that are strongly dependent on the availability of antibodies. Liquid chromatography, coupled to high-resolution mass spectrometry (LC-HRMS), has, therefore, been put forward as a relevant complementary method, but only for the detection of a limited number of enterotoxins. In this work, LC-HRMS was developed for the detection and quantification of 24 SEs. A database of 93 specific signature peptides and LC-HRMS parameters was optimized using sequences from 24 SEs, including their 162 variants. A label-free quantification protocol was established to overcome the absence of calibration standards. The LC-HRMS method showed high performance in terms of specificity, sensitivity, and accuracy when applied to 49 enterotoxin-producing strains. SE concentrations measured depended on both SE type and the coagulase-positive staphylococci (CPS) strain. This study indicates that LC-MS is a relevant alternative and complementary tool to ELISA methods. The advantages of LC-MS clearly lie in both the multiplex analysis of a large number of SEs, and the automated analysis of a high number of samples.

APA, Harvard, Vancouver, ISO, and other styles

5

Kritmetapak, Kittrawee, Louis A. Losbanos, Jolaine M. Hines, et al. "Chemical Characterization and Quantification of Circulating Intact PTH and PTH Fragments by High-Resolution Mass Spectrometry in Chronic Renal Failure." Clinical Chemistry 67, no. 6 (2021): 843–53. http://dx.doi.org/10.1093/clinchem/hvab013.

Full text

Abstract:

Abstract Background The precise concentrations of full-length parathyroid hormone (PTH1-84) and the identity and concentrations of PTH fragments in patients with various stages of chronic renal failure are unknown. Methods We developed a liquid chromatography-high resolution mass spectrometry (LC-HRMS) method to characterize and quantify PTH1-84 and PTH fragments in serum of 221 patients with progressive renal dysfunction. Following capture by matrix-bound amino-terminal or carboxyl-terminal region-specific antibodies and elution from matrix, PTH1-84 and PTH fragments were identified and quantitated using LC-HRMS. PTH was simultaneously measured using an intact PTH (iPTH) immunoassay. Results Full-length PTH1-84 and 8 PTH fragments (PTH28-84, 34-77, 34-84, 37-77, 37-84, 38-77, 38-84, and 45-84) were unequivocally identified and were shown to increase significantly when an eGFR declined to ≤17-23 mL/min/1.73m2. Serum concentrations of PTH1-84 were similar when measured by LC-HRMS following capture by amino-terminal or carboxyl-terminal immunocapture methods. In patients with an eGFR of &lt;30 mL/min/1.73 m2, serum PTH concentrations measured using LC-HRMS were significantly lower than PTH measured using an iPTH immunoassay. PTH7-84 and oxidized forms of PTH1-84 were below the limit of detection (30 and 50 pg/mL, respectively). Conclusions LC-HRMS identifies circulating PTH1-84, carboxyl-terminal PTH fragments, and mid-region PTH fragments, in patients with progressive renal failure. Serum PTH1-84 and its fragments markedly rise when an eGFR decreases to ≤17-23 mL/min/1.73 m2. PTH concentrations measured using LC-HRMS tend to be lower than those measured using an iPTH immunoassay, particularly in severe chronic renal failure. Our data do not support the existence of circulating PTH7-84 and oxidized PTH1-84.

APA, Harvard, Vancouver, ISO, and other styles

6

Liu, Ju, Jing Li, Chris Tran, et al. "Oligonucleotide quantification and metabolite profiling by high-resolution and accurate mass spectrometry." Bioanalysis 11, no. 21 (2019): 1967–80. http://dx.doi.org/10.4155/bio-2019-0137.

Full text

Abstract:

Aim: Advancements in RNA interference therapeutics have triggered development of improved bioanalytical methods for oligonucleotide metabolite profiling and high-throughput quantification in biological matrices. Results & methodology: HPLC coupled with high-resolution mass spectrometry (LC-HRMS) methods were developed to investigate the metabolism of a REVERSIR™ molecule in vivo. Plasma and tissue samples were extracted using solid-phase extraction followed by LC-HRMS analysis for metabolite profiling and quantification. The method was qualified from 10 to 5000 ng/ml (plasma) and 100 to 50000 ng/g (liver and kidney). In rat liver, intra and interday accuracy ranged from 80.9 to 118.5% and 88.4 to 111.9%, respectively, with acceptable precision (<20% CV). Conclusion: The LC-HRMS method can be applied for metabolite profiling and quantification of oligonucleotides in biological matrices.

APA, Harvard, Vancouver, ISO, and other styles

7

Luo, Y. R., C. Yun, K. L. Lynch, and K. Comstock. "A High-Resolution Liquid Chromatography-Mass Spectrometry Method for Identification of Toxic Natural Products in Clinical Cases." American Journal of Clinical Pathology 154, Supplement_1 (2020): S128. http://dx.doi.org/10.1093/ajcp/aqaa161.280.

Full text

Abstract:

Abstract Introduction/Objective Many natural products have biological effects on humans and animals. Poisoning caused by natural products is often found in clinical toxicology cases. Liquid chromatography-high-resolution-mass spectrometry (LC-HRMS) has recently emerged as a powerful analytical tool for large-scale target screening, and the application of LC-HRMS can be expanded to solve the clinical cases of natural product poisoning. Methods The LC-HRMS method is based on a spectral library of 121 natural products. The spectral library was constructed by analyzing standards either in a Q-TOF mass spectrometer (only MS2 spectra acquired) or in an Orbitrap Tribrid mass spectrometer (MS2 and MS3 spectra acquired). Results The LC-HRMS method was verified for the limit of detection (LOD) and matrix effects in both serum and urine matrices. For each compound, the LOD was evaluated from 1.0 ng/ml to 1000 ng/ml for urine samples and from 0.50 ng/ml to 500 ng/ml for serum samples. The matrix effects were determined at three concentration levels andranged from 30.4% to 123.5% for urine samples and from 23.4% to 132.9% for serum samples. The LC-HRMS method was successfully applied to identify the culprits in three clinical cases. In addition, the combined use of MS2 and MS3 spectra enhanced the accuracy of compound identification, in library search reducing the importance of retention time that varies among instruments and consumable lots. In Case 1, the patient presented with paresthesias, arrhythmias, and stiffened arms and legs. The toxic alkaloid aconitine was identified in the serum sample and the extract of herbs that the patient ingested. In Case 2, the patients presented with weakness, dizziness, and vomiting. The symptoms were caused by mistakenly taking Nicotiana glauca leaves and the alkaloid anabasine was identified as the culprit. In Case 3, the patients were suspected of intoxicated by taking too much extract of lupini beans. The culprit alkaloids from lupini beans lupanine and sparteine were found in the serum samples. Conclusion The involvement of a toxicology laboratory with the capability to perform the LC-HRMS method and with experience in the investigation of undifferentiated cases provides a unique diagnostic advantage in cases where exposure to toxic substances is possible.

APA, Harvard, Vancouver, ISO, and other styles

8

Chernonosov, Alexander, Liliya Aksenova, and Vladimir Koval. "The Development of a Liquid Chromatography High-Resolution Mass Spectrometric Method for Apixaban Quantification in Dried Plasma Spots in Parallel Reaction Monitoring Mode." Processes 9, no. 3 (2021): 450. http://dx.doi.org/10.3390/pr9030450.

Full text

Abstract:

This work aimed at developing and validating a rapid, sensitive, and robust method of liquid chromatography with high-resolution mass spectrometry (LC–HRMS) in parallel reaction monitoring (PRM) mode for apixaban quantification in dried plasma spots (DPSs) with a simple extraction procedure. A 25 µL sample of human plasma was placed onto Whatman 903 Protein Saver Cards and allowed to dry; 3.2 mm diameter disks were cut out from DPSs using a puncher, and 100 µL of a working internal standard solution was added to each sample. After this, they were vortexed on a shaker for 15 min at 800 rpm and 40 °C and quick centrifugation (10,000× g, 10 s), and then the extracts were transferred into a 300 µL vial for LC–HRMS. Data were acquired in PRM mode via detection of all target product ions with 10 ppm tolerance. Total analysis time was 5 min. The LC–HRMS method was validated for the 10–400 ng/mL range with R2 > 0.99. Within this range, intra- and interday variability of precision and accuracy was <10%, and recovery was 69.7–85.1%. Apixaban was stable after brief storage at room temperature, and at 4 °C for up to a month. The method development and validation results proved that this LC–HRMS assay of apixaban in DPSs is selective and robust.

APA, Harvard, Vancouver, ISO, and other styles

9

Wei, Cong, Louis S. Chupak, Thomas Philip, Benjamin M. Johnson, Robert Gentles, and Dieter M. Drexler. "Screening and Characterization of Reactive Compounds with In Vitro Peptide-Trapping and Liquid Chromatography/High-Resolution Accurate Mass Spectrometry." Journal of Biomolecular Screening 19, no. 2 (2013): 297–307. http://dx.doi.org/10.1177/1087057113492852.

Full text

Abstract:

The present study describes a novel methodology for the detection of reactive compounds using in vitro peptide-trapping and liquid chromatography–high-resolution accurate mass spectrometry (LC-HRMS). Compounds that contain electrophilic groups can covalently bind to nucleophilic moieties in proteins and form adducts. Such adducts are thought to be associated with drug-mediated toxicity and therefore represent potential liabilities in drug discovery programs. In addition, reactive compounds identified in biological screening can be associated with data that can be misinterpreted if the reactive nature of the compound is not appreciated. In this work, to facilitate the triage of hits from high-throughput screening (HTS), a novel assay was developed to monitor the formation of covalent peptide adducts by compounds suspected to be chemically reactive. The assay consists of in vitro incubations of test compounds (under conditions of physiological pH) with synthetically prepared peptides presenting a variety of nucleophilic moieties such as cysteine, lysine, histidine, arginine, serine, and tyrosine. Reaction mixtures were analyzed using full-scan LC-HRMS, the data were interrogated using postacquisition data mining, and modified amino acids were identified by subsequent LC-HRMS/mass spectrometry. The study demonstrated that in vitro nucleophilic peptide trapping followed by LC-HRMS analysis is a useful approach for screening of intrinsically reactive compounds identified from HTS exercises, which are then removed from follow-up processes, thus obviating the generation of data from biochemical activity assays.

APA, Harvard, Vancouver, ISO, and other styles

10

Kurniawati, Farida, Dona Fitria, Aan Risma Uli Nainggolan, and Puspita Ayu Wardani. "Identifikasi dan Karakterisasi Tanaman Kratom melalui Pendekatan Profil Kandungan Senyawa Penanda secara LC-HRMS QToF dan Penetapan Nilai Retention Index secara GCMS." Eruditio : Indonesia Journal of Food and Drug Safety 3, no. 1 (2023): 79–90. http://dx.doi.org/10.54384/eruditio.v3i1.141.

Full text

Abstract:

Saat ini senyawa penanda yang diperlukan sulit diperoleh di peredaran karena termasuk senyawa dilarang di Indonesia. Penelitian ini dilakukan untuk mengembangkan alternatif metode tanpa baku pembanding dengan pendekatan profil kandungan senyawa penanda menggunakan spektrometer massa. Spektrometri massa dilakukan baik menggunakan gas kromatografi maupun liquid chromatography high resolution mass spectrometry (LC-HRMS). Kedua metode tersebut dikembangkan untuk uji konfirmasi identitas senyawa penanda pada tanaman kratom. Uji spektrometri massa dilakukan setelah senyawa penanda diekstraksi dari tanaman. Uji gas kromatografi dilakukan menggunakan mode selected ion monitoring (SIM) pada m/z 214, 397, 383, dan 269. Sistem kromatografi LC-HRMS menggunakan modifier ion asam formiat 0.1% dalam air dan asetonitril sebagai fase gerak. Analisis dilakukan menggunakan spektrometer massa quadrupole time of flight (QToF) sebagai mass analyzer, mode ionisasi ESI+ dan mode scan. Analisis kualitatif menggunakan data waktu retensi (Rt) dan fragmen ion senyawa penanda tanaman kratom. Diperoleh 3 (tiga) senyawa penanda tanaman kratom, yaitu speciociliatine, speciogynine, dan mitragynine. Uji spesifisitas dilakukan dengan membandingkan waktu retensi yang dikonfirmasi dengan nilai Retention Index (RI) secara GCMS serta nilai m/z senyawa penanda secara LC-HRMS QToF. Hasil analisis menunjukkan bahwa 3 (tiga) senyawa penanda utama dapat digunakan dalam identifikasi tanaman kratom. Metode ini dapat diaplikasikan sebagai uji konfirmasi kandungan tanaman kratom dalam obat tradisional dimana metode LC-HRMS QToF merupakan meotode yang lebih sensitif dibandingkan dengan GCMS dengan nilai LOD 149.2 µg/g dan 67.6 mg/g sehingga dapat digunakan sebagai metode konfirmasi setelah sampel diekstraksi dan diisolasi secara KLT.

APA, Harvard, Vancouver, ISO, and other styles

11

LeBlanc, Patricia, Nadine Merkley, Krista Thomas, et al. "Isolation and Characterization of [D-Leu1]microcystin-LY from Microcystis aeruginosa CPCC-464." Toxins 12, no. 2 (2020): 77. http://dx.doi.org/10.3390/toxins12020077.

Full text

Abstract:

[D-Leu1]MC-LY (1) ([M + H]+ m/z 1044.5673, Δ 2.0 ppm), a new microcystin, was isolated from Microcystis aeruginosa strain CPCC-464. The compound was characterized by 1H and 13C NMR spectroscopy, liquid chromatography–high resolution tandem mass spectrometry (LC–HRMS/MS) and UV spectroscopy. A calibration reference material was produced after quantitation by 1H NMR spectroscopy and LC with chemiluminescence nitrogen detection. The potency of 1 in a protein phosphatase 2A inhibition assay was essentially the same as for MC-LR (2). Related microcystins, [D-Leu1]MC-LR (3) ([M + H]+ m/z 1037.6041, Δ 1.0 ppm), [D-Leu1]MC-M(O)R (6) ([M + H]+ m/z 1071.5565, Δ 2.0 ppm) and [D-Leu1]MC-MR (7) ([M + H]+ m/z 1055.5617, Δ 2.2 ppm), were also identified in culture extracts, along with traces of [D-Leu1]MC-M(O2)R (8) ([M + H]+ m/z 1087.5510, Δ 1.6 ppm), by a combination of chemical derivatization and LC–HRMS/MS experiments. The relative abundances of 1, 3, 6, 7 and 8 in a freshly extracted culture in the positive ionization mode LC–HRMS were ca. 84, 100, 3.0, 11 and 0.05, respectively. These and other results indicate that [D-Leu1]-containing MCs may be more common in cyanobacterial blooms than is generally appreciated but are easily overlooked with standard targeted LC–MS/MS screening methods.

APA, Harvard, Vancouver, ISO, and other styles

12

Ruth, Ashley C., Connie M. Gryniewicz-Ruzicka, Michael L. Trehy, Nicole Kornspan, and Gary Coody. "Consistency of Label Claims of Internet-Purchased Hemp Oil and Cannabis Products as Determined using IMS and LC-MS : A Marketplace Survey." Journal of Regulatory Science 4, no. 3 (2016): 1–6. http://dx.doi.org/10.21423/jrs-v04n03p001.

Full text

Abstract:

In this paper we describe the use of ion mobility spectrometry (IMS) and liquid chromatography – high resolution mass spectrometry (LC-HRMS) to screen for the presence of cannabinoids and other potential hazards in a set of products with hemp oil and/or cannabinoid label claims purchased via the internet. Preliminary screening was performed using IMS to examine the products for the presence of cannabinoids, illicit drugs or undeclared pharmaceuticals before analysis by LC-HRMS to quantitatively determine the presence of four of the most common naturally occurring cannabinoids while simultaneously qualitatively screening for the presence of nine of the most common cannabinoids. No other illicit drug or undeclared pharmaceutical was detected in any sample from IMS screening. Eighteen of twenty-three samples tested positive for the presence of at least one cannabinoid by LC-HRMS, with three products containing less than 0.01%(w/w) of a cannabinoid. Four products with explicit CBD label claims were found to not contain any CBD, while three products featured levels of cannabinoids below label claim.https://doi.org/10.21423/jrs-v04n03p001 (DOI assigned 5/31/2019)

APA, Harvard, Vancouver, ISO, and other styles

13

Marchand, Jérémy, Yann Guitton, Estelle Martineau, et al. "Extending the Lipidome Coverage by Combining Different Mass Spectrometric Platforms: An Innovative Strategy to Answer Chemical Food Safety Issues." Foods 10, no. 6 (2021): 1218. http://dx.doi.org/10.3390/foods10061218.

Full text

Abstract:

From a general public health perspective, a strategy combining non-targeted and targeted lipidomics MS-based approaches is proposed to identify disrupted patterns in serum lipidome upon growth promoter treatment in pigs. Evaluating the relative contributions of the platforms involved, the study aims at investigating the potential of innovative analytical approaches to highlight potential chemical food safety threats. Serum samples collected during an animal experiment involving control and treated pigs, whose food had been supplemented with ractopamine, were extracted and characterised using three MS strategies: Non-targeted RP LC-HRMS; the targeted Lipidyzer™ platform (differential ion mobility associated with shotgun lipidomics) and a homemade LC-HRMS triglyceride platform. The strategy enabled highlighting specific lipid profile patterns involving various lipid classes, mainly in relation to cholesterol esters, sphingomyelins, lactosylceramide, phosphatidylcholines and triglycerides. Thanks to the combination of non-targeted and targeted MS approaches, various compartments of the pig serum lipidome could be explored, including commonly characterised lipids (Lipidyzer™), triglyceride isomers (Triglyceride platform) and unique lipid features (non-targeted LC-HRMS). Thanks to their respective characteristics, the complementarity of the three tools could be demonstrated for public health purposes, with enhanced coverage, level of characterization and applicability.

APA, Harvard, Vancouver, ISO, and other styles

14

Bamberger, Michelle, Marika Nell, Ahmed H. Ahmed, et al. "Surface water and groundwater analysis using aryl hydrocarbon and endocrine receptor biological assays and liquid chromatography-high resolution mass spectrometry in Susquehanna County, PA." Environmental Science: Processes & Impacts 21, no. 6 (2019): 988–98. http://dx.doi.org/10.1039/c9em00112c.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Gören, Ahmet C., T. Cagdas Akalın, Şule Yalçın, and Ayşenur Gunaydin Akyildiz. "Determination of adulteration in hair serums by LC-HRMS §." Journal of Chemical Metrology, J (June 29, 2023): 93–99. http://dx.doi.org/10.25135/jcm.90.2304.2599.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Slobodchikova, Irina, Reajean Sivakumar, Md Samiur Rahman, and Dajana Vuckovic. "Characterization of Phase I and Glucuronide Phase II Metabolites of 17 Mycotoxins Using Liquid Chromatography—High-Resolution Mass Spectrometry." Toxins 11, no. 8 (2019): 433. http://dx.doi.org/10.3390/toxins11080433.

Full text

Abstract:

Routine mycotoxin biomonitoring methods do not include many mycotoxin phase I and phase II metabolites, which may significantly underestimate mycotoxin exposure especially for heavily metabolized mycotoxins. Additional research efforts are also needed to measure metabolites in vivo after exposure and to establish which mycotoxin metabolites should be prioritized for the inclusion during large-scale biomonitoring efforts. The objective of this study was to perform human in vitro microsomal incubations of 17 mycotoxins and systematically characterize all resulting metabolites using liquid chromatography–high-resolution mass spectrometry (LC-HRMS). The results obtained were then used to build a comprehensive LC-MS library and expand a validated 17-mycotoxin method for exposure monitoring to screening of additional 188 metabolites, including 100 metabolites reported for the first time. The final method represents one of the most comprehensive LC-HRMS methods for mycotoxin biomonitoring or metabolism/fate studies.

APA, Harvard, Vancouver, ISO, and other styles

17

Windarsih, Anjar, Nor Kartini Abu Bakar, Dachriyanus, Nancy Dewi Yuliana, Florentinus Dika Octa Riswanto, and Abdul Rohman. "Analysis of Pork in Beef Sausages Using LC-Orbitrap HRMS Untargeted Metabolomics Combined with Chemometrics for Halal Authentication Study." Molecules 28, no. 16 (2023): 5964. http://dx.doi.org/10.3390/molecules28165964.

Full text

Abstract:

Beef sausage (BS) is one of the most favored meat products due to its nutrition and good taste. However, for economic purposes, BS is often adulterated with pork by unethical players. Pork consumption is strictly prohibited for religions including Islam and Judaism. Therefore, advanced detection methods are highly required to warrant the halal authenticity of BS. This research aimed to develop a liquid chromatography–high-resolution mass spectrometry (LC–HRMS) method to determine the halal authenticity of BS using an untargeted metabolomics approach. LC–HRMS was capable of detecting various metabolites in BS and BS containing pork. The presence of pork in BS could be differentiated using principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) with high accuracy. PLS-DA perfectly classified authentic BS and BS containing pork in all concentration levels of pork with R2X = (0.821), R2Y(= 0.984), and Q2 = (0.795). The level of pork in BS was successfully predicted through partial least squares (PLS) and orthogonal PLS (OPLS) chemometrics. Both models gave high R2 (>0.99) actual and predicted values as well as few errors, indicating good accuracy and precision. Identification of discriminating metabolites’ potential as biomarker candidates through variable importance for projections (VIP) value revealed metabolites of 2-arachidonyl-sn-glycero-3-phosphoethanolamine, 3-hydroxyoctanoylcarnitine, 8Z,11Z,14Z-eicosatrienoic acid, D-(+)-galactose, oleamide, 3-hydroxyhexadecanoylcarnitine, arachidonic acid, and α-eleostearic acid as good indicators to detect pork. It can be concluded that LC–HRMS metabolomics combined with PCA, PLS-DA, PLS, and OPLS was successfully used to detect pork adulteration in beef sausages. The results imply that LC–HRMS untargeted metabolomics in combination with chemometrics is a promising alternative as an analytical technique to detect pork in sausage products. Further analysis of larger samples is required to warrant the reproducibility.

APA, Harvard, Vancouver, ISO, and other styles

18

Aksenova, Liliya V., Vladimir V. Koval, and Alexander A. Chernonosov. "Parallel Reaction Monitoring Mode for Atenolol Quantification in Dried Plasma Spots by Liquid Chromatography Coupled with High-Resolution Mass Spectrometry." Processes 10, no. 7 (2022): 1240. http://dx.doi.org/10.3390/pr10071240.

Full text

Abstract:

In this study, we reported a rapid, sensitive, robust, and validated method for atenolol quantification in dried plasma spots (DPS) by liquid chromatography with high-resolution mass spectrometry (LC-HRMS) using parallel reaction monitoring mode (PRM). Aliquots of 25 µL human plasma were placed onto Whatman 903 Cards and air-dried. Disks (3.2 mm internal diameter) were punched, and a 100 µL working internal standard solution was added to each sample and then incubated on a shaker for 15 min at 40 °C, followed by rapid centrifugation (10,000× g, 10 s). The supernatant was transferred into 300 µL vials for subsequent LC–HRMS analysis. After chromatographic separation, atenolol and the internal standard were quantified in positive-ion parallel reaction monitoring mode by detection of all target product ions at 10 ppm tolerances. The total time of the analysis was 5 min. The calibration curve was linear in the range of 5–1000 ng/mL with interday and intraday precision levels and biases of <14.4%, and recovery was 62.9–81.0%. The atenolol in DPS was stable for ≥30 days at 25 and 4 °C. This fully validated method is selective and suitable for atenolol quantitation in DPS using LC–HRMS.

APA, Harvard, Vancouver, ISO, and other styles

19

Kryuchkov, Fedor, Alison Robertson, Elizabeth M. Mudge, Christopher O. Miles, Soetkien Van Gothem, and Silvio Uhlig. "Reductive Amination for LC–MS Signal Enhancement and Confirmation of the Presence of Caribbean Ciguatoxin-1 in Fish." Toxins 14, no. 6 (2022): 399. http://dx.doi.org/10.3390/toxins14060399.

Full text

Abstract:

Ciguatera poisoning is a global health concern caused by the consumption of seafood containing ciguatoxins (CTXs). Detection of CTXs poses significant analytical challenges due to their low abundance even in highly toxic fish, the diverse and in-part unclarified structures of many CTX congeners, and the lack of reference standards. Selective detection of CTXs requires methods such as liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) or high-resolution MS (LC–HRMS). While HRMS data can provide greatly improved resolution, it is typically less sensitive than targeted LC–MS/MS and does not reliably comply with the FDA guidance level of 0.1 µg/kg CTXs in fish tissue that was established for Caribbean CTX-1 (C-CTX-1). In this study, we provide a new chemical derivatization approach employing a fast and simple one-pot derivatization with Girard’s reagent T (GRT) that tags the C-56-ketone intermediate of the two equilibrating C-56 epimers of C-CTX-1 with a quaternary ammonium moiety. This derivatization improved the LC–MS/MS and LC–HRMS responses to C-CTX-1 by approximately 40- and 17-fold on average, respectively. These improvements in sensitivity to the GRT-derivative of C-CTX-1 are attributable to: the improved ionization efficiency caused by insertion of a quaternary ammonium ion; the absence of adduct-ions and water-loss peaks for the GRT derivative in the mass spectrometer, and; the prevention of on-column epimerization (at C-56 of C-CTX-1) by GRT derivatization, leading to much better chromatographic peak shapes. This C-CTX-1–GRT derivatization strategy mitigates many of the shortcomings of current LC–MS analyses for C-CTX-1 by improving instrument sensitivity, while at the same time adding selectivity due to the reactivity of GRT with ketones and aldehydes.

APA, Harvard, Vancouver, ISO, and other styles

20

Jiang, Meng-Ying, Yun-Qing Huang, Jie-Mei Chu, et al. "A magnetic ZrO2 based solid-phase extraction strategy for selective enrichment and profiling of glycosylated compounds in rice." Analytical Methods 8, no. 34 (2016): 6436–43. http://dx.doi.org/10.1039/c6ay01383j.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Lucci, Paolo, Javier Saurina, and Oscar Núñez. "Trends in LC-MS and LC-HRMS analysis and characterization of polyphenols in food." TrAC Trends in Analytical Chemistry 88 (March 2017): 1–24. http://dx.doi.org/10.1016/j.trac.2016.12.006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Alygizakis, Nikiforos, Vasileios Konstantakos, Grigoris Bouziotopoulos, Evangelos Kormentzas, Jaroslav Slobodnik, and Nikolaos S. Thomaidis. "A Multi-Label Classifier for Predicting the Most Appropriate Instrumental Method for the Analysis of Contaminants of Emerging Concern." Metabolites 12, no. 3 (2022): 199. http://dx.doi.org/10.3390/metabo12030199.

Full text

Abstract:

Liquid chromatography-high resolution mass spectrometry (LC-HRMS) and gas chromatography-high resolution mass spectrometry (GC-HRMS) have revolutionized analytical chemistry among many other disciplines. These advanced instrumentations allow to theoretically capture the whole chemical universe that is contained in samples, giving unimaginable opportunities to the scientific community. Laboratories equipped with these instruments produce a lot of data daily that can be digitally archived. Digital storage of data opens up the opportunity for retrospective suspect screening investigations for the occurrence of chemicals in the stored chromatograms. The first step of this approach involves the prediction of which data is more appropriate to be searched. In this study, we built an optimized multi-label classifier for predicting the most appropriate instrumental method (LC-HRMS or GC-HRMS or both) for the analysis of chemicals in digital specimens. The approach involved the generation of a baseline model based on the knowledge that an expert would use and the generation of an optimized machine learning model. A multi-step feature selection approach, a model selection strategy, and optimization of the classifier’s hyperparameters led to a model with accuracy that outperformed the baseline implementation. The models were used to predict the most appropriate instrumental technique for new substances. The scripts are available at GitHub and the dataset at Zenodo.

APA, Harvard, Vancouver, ISO, and other styles

23

Lotfy, Momen M., Ahmed M. Sayed, Asmaa M. AboulMagd, et al. "Metabolomic profiling, biological evaluation of Aspergillus awamori, the river Nile-derived fungus using epigenetic and OSMAC approaches." RSC Advances 11, no. 12 (2021): 6709–19. http://dx.doi.org/10.1039/d0ra07578g.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Flores, Cintia, and Josep Caixach. "High Levels of Anabaenopeptins Detected in a Cyanobacteria Bloom from N.E. Spanish Sau-Susqueda-El Pasteral Reservoirs System by LC–HRMS." Toxins 12, no. 9 (2020): 541. http://dx.doi.org/10.3390/toxins12090541.

Full text

Abstract:

The appearance of a bloom of cyanobacteria in the Sau-Susqueda-El Pasteral system (River Ter, NE Spain) in the autumn of 2015 has been the most recent episode of extensive bloom detected in Catalonia. This system is devoted mainly to urban supply, regulation of the river, irrigation and production of hydroelectric energy. In fact, it is one of the main supply systems for the metropolitan area of cities such as Barcelona and Girona. An assessment and management plan was implemented in order to minimize the risk associated to cyanobacteria. The reservoir was confined and periodic sampling was carried out. Low and high toxicity was detected by cell bioassays with human cell lines. Additionally, analysis studies were performed by enzyme-linked immunosorbent assay (ELISA) and liquid chromatography–high resolution mass spectrometry (LC–HRMS). A microcystin target analysis and suspect screening of microcystins, nodularins, cylindrosperpmopsin and related cyanobacterial peptides by LC–HRMS were applied. The results for the analysis of microcystins were negative (<0.3 μg/L) in all the surface samples. Only traces of microcystin-LR, -RR and -dmRR were detected by LC–HRMS in a few ng/L from both fractions, aqueous and sestonic. In contrast, different anabaenopeptins and oscillamide Y at unusually high concentrations (µg-mg/L) were observed. To our knowledge, no previous studies have detected these bioactive peptides at such high levels. The reliable identification of these cyanobacterial peptides was achieved by HRMS. Although recently these peptides are detected frequently worldwide, these bioactive compounds have received little attention. Therefore, more studies on these substances are recommended, especially on their toxicity, health risk and presence in water resources.

APA, Harvard, Vancouver, ISO, and other styles

25

Chang, Wei, Genye He, Kuan Yan, et al. "Doping control analysis of small peptides in human urine using LC-HRMS with parallel reaction monitoring mode: screening and confirmation." Analytical Methods 13, no. 48 (2021): 5838–50. http://dx.doi.org/10.1039/d1ay01677f.

Full text

Abstract:

This study described a reliable analytical method, which combines solid-phase extraction with LC-HRMS employing the parallel reaction monitoring mode, for screening and confirming small peptides in human urine.

APA, Harvard, Vancouver, ISO, and other styles

26

Qu, Lihua, Wenjun Wang, Debin Zeng, Yaxin Lu, and Zheng Yin. "Quantitative performance of online SPE-LC coupled to Q-Exactive for the analysis of sofosbuvir in human plasma." RSC Advances 5, no. 119 (2015): 98269–77. http://dx.doi.org/10.1039/c5ra20233g.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Hemmer, Selina, Sascha K. Manier, Svenja Fischmann, Folker Westphal, Lea Wagmann, and Markus R. Meyer. "Comparison of Three Untargeted Data Processing Workflows for Evaluating LC-HRMS Metabolomics Data." Metabolites 10, no. 9 (2020): 378. http://dx.doi.org/10.3390/metabo10090378.

Full text

Abstract:

The evaluation of liquid chromatography high-resolution mass spectrometry (LC-HRMS) raw data is a crucial step in untargeted metabolomics studies to minimize false positive findings. A variety of commercial or open source software solutions are available for such data processing. This study aims to compare three different data processing workflows (Compound Discoverer 3.1, XCMS Online combined with MetaboAnalyst 4.0, and a manually programmed tool using R) to investigate LC-HRMS data of an untargeted metabolomics study. Simple but highly standardized datasets for evaluation were prepared by incubating pHLM (pooled human liver microsomes) with the synthetic cannabinoid A-CHMINACA. LC-HRMS analysis was performed using normal- and reversed-phase chromatography followed by full scan MS in positive and negative mode. MS/MS spectra of significant features were subsequently recorded in a separate run. The outcome of each workflow was evaluated by its number of significant features, peak shape quality, and the results of the multivariate statistics. Compound Discoverer as an all-in-one solution is characterized by its ease of use and seems, therefore, suitable for simple and small metabolomic studies. The two open source solutions allowed extensive customization but particularly, in the case of R, made advanced programming skills necessary. Nevertheless, both provided high flexibility and may be suitable for more complex studies and questions.

APA, Harvard, Vancouver, ISO, and other styles

28

Mantzourani, Christiana, and Maroula G. Kokotou. "Targeted and Suspect Fatty Acid Profiling of Royal Jelly by Liquid Chromatography—High Resolution Mass Spectrometry." Biomolecules 13, no. 3 (2023): 424. http://dx.doi.org/10.3390/biom13030424.

Full text

Abstract:

Royal jelly (RJ) is a bee product produced by the mandibular and hypopharyngeal glands of worker honeybees which has attracted special attention because of its numerous pharmacological activities and its applications to dermatology and cosmetics. In 2020, we demonstrated a liquid chromatography–high resolution mass spectrometry (LC–HRMS) method for the determination of seven medium-chain FFAs in RJ samples. The aim of the present work was to extend our studies on FA profiling of RJ, exploring the presence of common long-chain saturated, mono-unsaturated and poly-unsaturated free FAs in RJ samples using this LC–HRMS method. Among twenty common FAs studied by a targeted approach, palmitic acid, stearic acid and oleic acid were found at concentrations higher than the rest of the FAs (the concentrations of these three acids ranged from 37.4 to 48.0, from 17.7 to 24.0 and from 9.4 to 11.1 mg/100 g of fresh RJ, respectively). The high mass accuracy of LC–HRMS allowed the application of a suspect approach, which enabled the exploration of various C9 and C11 FAs, as well as hydroxylated C12 FAs. Nonenoic acid was indicated as the most abundant among these acids. In addition, for the first time, the presence of a variety of regio-isomers of hydroxymyristic, hydroxypalmitic and hydroxystearic acids was demonstrated in RJ samples.

APA, Harvard, Vancouver, ISO, and other styles

29

Windarsih, Anjar, Florentinus Dika Octa Riswanto, Nor Kartini Abu Bakar, Nancy Dewi Yuliana, Dachriyanus, and Abdul Rohman. "Detection of Pork in Beef Meatballs Using LC-HRMS Based Untargeted Metabolomics and Chemometrics for Halal Authentication." Molecules 27, no. 23 (2022): 8325. http://dx.doi.org/10.3390/molecules27238325.

Full text

Abstract:

Adulteration of high-quality meat products using lower-priced meats, such as pork, is a crucial issue that could harm consumers. The consumption of pork is strictly forbidden in certain religions, such as Islam and Judaism. Therefore, the objective of this research was to develop untargeted metabolomics using liquid chromatography-high resolution mass spectrometry (LC-HRMS) combined with chemometrics for analysis of pork in beef meatballs for halal authentication. We investigated the use of non-targeted LC-HRMS as a method to detect such food adulteration. As a proof of concept using six technical replicates of pooled samples from beef and pork meat, we could show that metabolomics using LC-HRMS could be used for high-throughput screening of metabolites in meatballs made from beef and pork. Chemometrics of principal component analysis (PCA) was successfully used to differentiate beef meatballs and pork meatball samples. Partial least square-discriminant analysis (PLS-DA) clearly discriminated between halal and non-halal beef meatball samples with 100% accuracy. Orthogonal projection to latent structures-discriminant analysis (OPLS-DA) perfectly discriminated and classified meatballs made from beef, pork, and a mixture of beef-pork with a good level of fitness (R2X = 0.88, R2Y = 0.71) and good predictivity (Q2 = 0.55). Partial least square (PLS) and orthogonal PLS (OPLS) were successfully applied to predict the concentration of pork present in beef meatballs with high accuracy (R2 = 0.99) and high precision. Thirty-five potential metabolite markers were identified through VIP (variable important for projections) analysis. Metabolites of 1-(1Z-hexadecenyl)-sn-glycero-3-phosphocholine, acetyl-l-carnitine, dl-carnitine, anserine, hypoxanthine, linoleic acid, and prolylleucine had important roles for predicting pork in beef meatballs through S-line plot analysis. It can be concluded that a combination of untargeted metabolomics using LC-HRMS and chemometrics is promising to be developed as a standard analytical method for halal authentication of highly processed meat products.

APA, Harvard, Vancouver, ISO, and other styles

30

Lin, Xiao, Ling Chai, Hong Rui Zhu, et al. "Applying molecular networking for targeted isolation of depsipeptides." RSC Advances 11, no. 5 (2021): 2774–82. http://dx.doi.org/10.1039/d0ra09388b.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Sasse, Michael, and Matthias Rainer. "Mass Spectrometric Methods for Non-Targeted Screening of Metabolites: A Future Perspective for the Identification of Unknown Compounds in Plant Extracts." Separations 9, no. 12 (2022): 415. http://dx.doi.org/10.3390/separations9120415.

Full text

Abstract:

Phyto products are widely used in natural products, such as medicines, cosmetics or as so-called “superfoods”. However, the exact metabolite composition of these products is still unknown, due to the time-consuming process of metabolite identification. Non-target screening by LC-HRMS/MS could be a technique to overcome these problems with its capacity to identify compounds based on their retention time, accurate mass and fragmentation pattern. In particular, the use of computational tools, such as deconvolution algorithms, retention time prediction, in silico fragmentation and sophisticated search algorithms, for comparison of spectra similarity with mass spectral databases facilitate researchers to conduct a more exhaustive profiling of metabolic contents. This review aims to provide an overview of various techniques and tools for non-target screening of phyto samples using LC-HRMS/MS.

APA, Harvard, Vancouver, ISO, and other styles

32

You, Youwen, Rachel M. Proctor, Kevin Guo, et al. "Use of high resolution/accurate mass full scan/data-dependent acquisition for targeted/non-targeted screening in equine doping control." Analytical Methods 13, no. 13 (2021): 1565–75. http://dx.doi.org/10.1039/d0ay02297g.

Full text

Abstract:

A targeted/non-targeted LC-HRMS/MS method for equine doping screening analysis was developed using a QE-Plus Orbitrap mass spectrometer combined with an in-house built compound database and spectral library.

APA, Harvard, Vancouver, ISO, and other styles

33

Verougstraete, Nick, and Alain Verstraete. "Identification of etazene metabolites in human urine by LC-HRMS." Toxicologie Analytique et Clinique 34, no. 3 (2022): S60. http://dx.doi.org/10.1016/j.toxac.2022.06.076.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Vargas-Medina, Lorena, Lydia F. Yamaguchi, and Ericsson Coy-Barrera. "LC-ESI-HRMS-Based Chemical Characterization of Lupinus bogotensis Roots." Revista Facultad de Ciencias Básicas 12, no. 2 (2016): 200–211. http://dx.doi.org/10.18359/rfcb.2028.

Full text

Abstract:

Plants of the genus Lupinus (Fabaceae) have been studied due to the occurrence of different compounds, especially those possessing quinolizidine and isoflavone-like structures. These kinds of compounds are characterized by both medical and industrial applications, providing various benefits to human being. However, organs such as roots have not been equally studied and there is a lack of such records for native species. Therefore, in the present study, the chemical composition of nodulated roots from greenhouse-established L. bogotensis plants was determined. The resulting crude ethanolic extract was then analyzed by LC/HRMS and chemical nature of most compounds was determined by analyzing the high resolution mass spectra. Recorded profile showed adequate separation allowing tentative identification of detected compounds. 47 secondary metabolites (mainly isoflavones and quinolizidine-type compounds) were thus identified. Most phenolic compounds were found to be conjugated flavonoids (e.g., genistin and genistein malonylglucoside) and lupanine, sparteine and hydroxylupanine were noticed as the main alkaloids. Among alkaloid-like compounds, dehydromitomycin C, a compound produced by Streptomyces caespitosus was identified. Lupadienediol (a lupane-type triterpene recognized for being involved in rhizobacteria:legumes symbiosis) was the only terpene-related component identified in the extract. The present work corresponds to the first report on the chemical composition of L. bogotensis root and constitutes an adequate basis for phytoconstituents finding from nature to support the use of native species.

APA, Harvard, Vancouver, ISO, and other styles

35

Kunzelmann, Marco, Martin Winter, Magnus Åberg, Karl-Erik Hellenäs, and Johan Rosén. "Non-targeted analysis of unexpected food contaminants using LC-HRMS." Analytical and Bioanalytical Chemistry 410, no. 22 (2018): 5593–602. http://dx.doi.org/10.1007/s00216-018-1028-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Olesti, Eulalia, Arnaud Garcia, Rita Rahban, et al. "Steroid profile analysis by LC-HRMS in human seminal fluid." Journal of Chromatography B 1136 (January 2020): 121929. http://dx.doi.org/10.1016/j.jchromb.2019.121929.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Qiu, Jiangbing, Elliott J. Wright, Krista Thomas, Aifeng Li, Pearse McCarron, and Daniel G. Beach. "Semiquantitation of Paralytic Shellfish Toxins by Hydrophilic Interaction Liquid Chromatography-Mass Spectrometry Using Relative Molar Response Factors." Toxins 12, no. 6 (2020): 398. http://dx.doi.org/10.3390/toxins12060398.

Full text

Abstract:

Paralytic shellfish toxins (PSTs) are a complex class of analogs of the potent neurotoxin saxitoxin (STX). Since calibration standards are not available for many PSTs, including C-11 hydroxyl analogs called M-toxins, accurate quantitation by liquid chromatography–mass spectrometry (LC-MS) can be challenging. In the absence of standards, PSTs are often semiquantitated using standards of a different analog (e.g., STX), an approach with a high degree of uncertainty due to the highly variable sensitivity between analytes in electrospray ionization. Here, relative molar response factors (RMRs) were investigated for a broad range of PSTs using common LC-MS approaches in order to improve the quantitation of PSTs for which standards are unavailable. First, several M-toxins (M1-M6, M9 and dcM6) were semipurified from shellfish using preparative gel filtration chromatography and quantitated using LC-charged aerosol detection (LC-CAD). The RMRs of PST certified reference materials (CRMs) and M-toxins were then determined using selective reaction monitoring LC-MS/MS and full scan LC-high-resolution MS (LC-HRMS) methods in positive and negative electrospray ionization. In general, RMRs for PSTs with similar chemical structures were comparable, but varied significantly between subclasses, with M-toxins showing the lowest sensitivity. For example, STX showed a greater than 50-fold higher RMR than M4 and M6 by LC-HRMS. The MS instrument, scan mode and polarity also had significant impacts on RMRs and should be carefully considered when semiquantitating PSTs by LC-MS. As a demonstration of their utility, the RMRs determined were applied to the semiquantitation of PSTs in contaminated mussels, showing good agreement with results from calibration with CRMs.

APA, Harvard, Vancouver, ISO, and other styles

38

Albergamo, Vittorio, Beate I. Escher, Emma L. Schymanski, et al. "Evaluation of reverse osmosis drinking water treatment of riverbank filtrate using bioanalytical tools and non-target screening." Environmental Science: Water Research & Technology 6, no. 1 (2020): 103–16. http://dx.doi.org/10.1039/c9ew00741e.

Full text

Abstract:

Organic micropollutants that occurred in a natural drinking water source induced effects that were not detectable after reverse osmosis. Bioactive compounds were characterised by non-target screening of LC-HRMS data using open cheminformatics approaches.

APA, Harvard, Vancouver, ISO, and other styles

39

Haiß, Annette, Andrew Jordan, Janin Westphal, Evgenia Logunova, Nicholas Gathergood, and Klaus Kümmerer. "On the way to greener ionic liquids: identification of a fully mineralizable phenylalanine-based ionic liquid." Green Chemistry 18, no. 16 (2016): 4361–73. http://dx.doi.org/10.1039/c6gc00417b.

Full text

Abstract:

Biodegradability screening ofl-phenylalanine based ILs and LC-HRMS analysis of the degradation products led to the identification of a pyridinium IL which was fully mineralizable and is proposed as a basic structure for green ILs.

APA, Harvard, Vancouver, ISO, and other styles

40

D'Urso, Gilda, Assunta Napolitano, Ciro Cannavacciuolo, Milena Masullo, and Sonia Piacente. "Okra fruit: LC-ESI/LTQOrbitrap/MS/MSn based deep insight on polar lipids and specialized metabolites with evaluation of anti-oxidant and anti-hyperglycemic activity." Food & Function 11, no. 9 (2020): 7856–65. http://dx.doi.org/10.1039/d0fo00867b.

Full text

Abstract:

The chemical composition of okra fruit was analysed by LC-HRMS. Metabolites belonging to different polar lipid classes, along with phenolic acids and flavonoids were identified. The antioxidant activity and inhibition of α-glucosidase were assayed.

APA, Harvard, Vancouver, ISO, and other styles

41

Klijnstra, Mirjam, and Arjen Gerssen. "A Sensitive LC-MS/MS Method for Palytoxin Using Lithium Cationization." Toxins 10, no. 12 (2018): 537. http://dx.doi.org/10.3390/toxins10120537.

Full text

Abstract:

Palytoxin (PlTX) and analogues are produced by certain dinoflagellates, sea anemones, corals and cyanobacteria. PlTX can accumulate in the food chain and when consumed it may cause intoxication with symptoms like myalgia, weakness, fever, nausea, and vomiting. The analysis of PlTXs is challenging, and because of the large molecular structure, it is difficult to develop a sensitive and selective liquid chromatography-mass spectrometry (LC-MS/MS) method. In this work, an LC-MS/MS method was developed to analyse PlTXs with use of lithium iodine and formic acid as additives in the mobile phase. For method development, initially, LC-hrMS was used to accurately determine the elemental composition of the precursor and product ions. The main adduct formed was [M + H + 2Li]3+. Fragments were identified with LC-hrMS and these were incorporated in the LC-MS/MS method. A method of 10 min was developed and a solid phase extraction clean-up procedure was optimised for shellfish matrix. The determined limits of detection were respectively 8 and 22 µg PlTX kg−1 for mussel and oyster matrix. Oysters gave a low recovery of approximately 50% for PlTX during extraction. The method was successfully in-house validated, repeatability had a relative standard deviation less than 20% (n = 5) at 30 µg PlTX kg−1 in mussel, cockle, and ensis, and at 60 µg PlTX kg−1 in oyster.

APA, Harvard, Vancouver, ISO, and other styles

42

Ramadhan, Muhammad Fajri, Endang Astuti, and Respati Tri Swasono. "Screening and Toxicity Assay of Bioactive Compounds from Ethyl Acetate Extract of Indonesian Marine Sponge <i>Dysidia </i>sp<i>.</i> from Hoga Island." Materials Science Forum 1061 (May 26, 2022): 165–71. http://dx.doi.org/10.4028/p-rg4242.

Full text

Abstract:

Screening of the toxic active compounds from the ethyl acetate fraction of the sponge Dysidea sp. from Hoga Island, Wakatobi National Park. This study aims to determine the toxic properties of the ethyl acetate fraction of sponge Dysidea sp. Isolation was carried out by extraction method using methanol as solvent, then the extract was partitioned using various solvents, such as N-Hexane, Dichloromethane, Ethyl Acetate and Acetone. The obtained fraction was then tested for toxicity using the Brine Shrimp Lethality Test (BSLT) and phytochemical tests. Identification of compounds from the fraction that have toxic properties were then identified using Liquid Chromatography – High Resolution Mass Spectrometry (LC-HRMS). The ethyl acetate fraction obtained was 1.5 grams in the form of a green solid paste. LC-HRMS analysis showed that the ethyl acetate fraction contained 3 reported compounds and 2 unreported compounds.

APA, Harvard, Vancouver, ISO, and other styles

43

Estevez, Pablo, Manoella Sibat, José Manuel Leão-Martins, Pedro Reis Costa, Ana Gago-Martínez, and Philipp Hess. "Liquid Chromatography Coupled to High-Resolution Mass Spectrometry for the Confirmation of Caribbean Ciguatoxin-1 as the Main Toxin Responsible for Ciguatera Poisoning Caused by Fish from European Atlantic Coasts." Toxins 12, no. 4 (2020): 267. http://dx.doi.org/10.3390/toxins12040267.

Full text

Abstract:

Ciguatera poisoning (CP) is a common seafood intoxication mainly caused by the consumption of fish contaminated by ciguatoxins. Recent studies showed that Caribbean ciguatoxin-1 (C-CTX1) is the main toxin causing CP through fish caught in the Northeast Atlantic, e.g., Canary Islands (Spain) and Madeira (Portugal). The use of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) combined with neuroblastoma cell assay (N2a) allowed the initial confirmation of the presence of C-CTX1 in contaminated fish samples from the abovementioned areas, nevertheless the lack of commercially available reference materials for these particular ciguatoxin (CTX) analogues has been a major limitation to progress research. The EuroCigua project allowed the preparation of C-CTX1 laboratory reference material (LRM) from fish species (Seriola fasciata) from the Madeira archipelago (Portugal). This reference material was used to implement a liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) for the detection of C-CTX1, acquisition of full-scan as well as collision-induced mass spectra of this particular analogue. Fragmentation pathways were proposed based on fragments obtained. The optimized LC-HRMS method was then applied to confirm C-CTX1 in fish (Bodianus scrofa) caught in the Selvagens Islands (Portugal).

APA, Harvard, Vancouver, ISO, and other styles

44

Kotapati, Srikanth, Madhura Deshpande, Aarti Jashnani, Dharam Thakkar, Hongwu Xu, and Gavin Dollinger. "The role of ligand-binding assay and LC–MS in the bioanalysis of complex protein and oligonucleotide therapeutics." Bioanalysis 13, no. 11 (2021): 931–54. http://dx.doi.org/10.4155/bio-2021-0009.

Full text

Abstract:

Ligand-binding assay (LBA) and LC–MS have been the preferred bioanalytical techniques for the quantitation and biotransformation assessment of various therapeutic modalities. This review provides an overview of the applications of LBA, LC–MS/MS and LC–HRMS for the bioanalysis of complex protein therapeutics including antibody–drug conjugates, fusion proteins and PEGylated proteins as well as oligonucleotide therapeutics. The strengths and limitations of LBA and LC–MS, along with some guidelines on the choice of appropriate bioanalytical technique(s) for the bioanalysis of these therapeutic modalities are presented. With the discovery of novel and more complex therapeutic modalities, there is an increased need for the biopharmaceutical industry to develop a comprehensive bioanalytical strategy integrating both LBA and LC–MS.

APA, Harvard, Vancouver, ISO, and other styles

45

Kintz, Pascal, Alice Ameline, Laurie Gheddar, and Jean‐Sébastien Raul. "Testing for GW501516 (cardarine) in human hair using LC/MS–MS and confirmation by LC/HRMS." Drug Testing and Analysis 12, no. 7 (2020): 980–86. http://dx.doi.org/10.1002/dta.2802.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Millet, Aurélien, Nihel Khoudour, Dorothée Lebert, et al. "Development, Validation, and Comparison of Two Mass Spectrometry Methods (LC-MS/HRMS and LC-MS/MS) for the Quantification of Rituximab in Human Plasma." Molecules 26, no. 5 (2021): 1383. http://dx.doi.org/10.3390/molecules26051383.

Full text

Abstract:

Rituximab is a chimeric immunoglobulin G1-kappa (IgG1κ) antibody targeting the CD20 antigen on B-lymphocytes. Its applications are various, such as for the treatment of chronic lymphoid leukemia or non-Hodgkin’s lymphoma in oncology, and it can also be used in the treatment of certain autoimmune diseases. Several studies support the interest in therapeutic drug monitoring to optimize dosing regimens of rituximab. Thus, two different laboratories have developed accurate and reproductive methods to quantify rituximab in human plasma: one using liquid chromatography quadripolar tandem mass spectrometer (LC-MS/MS) and the other, liquid chromatography orbitrap tandem mass spectrometer (LC-MS/HRMS). For both assays, quantification was based on albumin depletion or IgG-immunocapture, surrogate peptide analysis, and full-length stable isotope-labeled rituximab. With LC-MS/MS, the concentration range was from 5 to 500 µg/mL, the within- and between-run precisions were <8.5%, and the limit of quantitation was 5 µg/mL. With LC-MS/HRMS, the concentration range was from 10 to 200 µg/mL, the within- and between-run accuracy were <11.5%, and the limit of quantitation was 2 µg/mL. Rituximab plasma concentrations from 63 patients treated for vasculitis were compared. Bland–Altman analysis and Passing–Bablok regression showed the interchangeability between these two methods. Overall, these methods were robust and reliable and could be applied to routine clinical samples.

APA, Harvard, Vancouver, ISO, and other styles

47

Malm, Louise, Emma Palm, Amina Souihi, Merle Plassmann, Jaanus Liigand, and Anneli Kruve. "Guide to Semi-Quantitative Non-Targeted Screening Using LC/ESI/HRMS." Molecules 26, no. 12 (2021): 3524. http://dx.doi.org/10.3390/molecules26123524.

Full text

Abstract:

Non-targeted screening (NTS) with reversed phase liquid chromatography electrospray ionization high resolution mass spectrometry (LC/ESI/HRMS) is increasingly employed as an alternative to targeted analysis; however, it is not possible to quantify all compounds found in a sample with analytical standards. As an alternative, semi-quantification strategies are, or at least should be, used to estimate the concentrations of the unknown compounds before final decision making. All steps in the analytical chain, from sample preparation to ionization conditions and data processing can influence the signals obtained, and thus the estimated concentrations. Therefore, each step needs to be considered carefully. Generally, less is more when it comes to choosing sample preparation as well as chromatographic and ionization conditions in NTS. By combining the positive and negative ionization mode, the performance of NTS can be improved, since different compounds ionize better in one or the other mode. Furthermore, NTS gives opportunities for retrospective analysis. In this tutorial, strategies for semi-quantification are described, sources potentially decreasing the signals are identified and possibilities to improve NTS are discussed. Additionally, examples of retrospective analysis are presented. Finally, we present a checklist for carrying out semi-quantitative NTS.

APA, Harvard, Vancouver, ISO, and other styles

48

van Herwerden, Denice, Jake W. O'Brien, Phil M. Choi, Kevin V. Thomas, Peter J. Schoenmakers, and Saer Samanipour. "Naive Bayes classification model for isotopologue detection in LC-HRMS data." Chemometrics and Intelligent Laboratory Systems 223 (April 2022): 104515. http://dx.doi.org/10.1016/j.chemolab.2022.104515.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Narduzzi, Luca, Anne-Lise Royer, Emmanuelle Bichon, et al. "Ammonium Fluoride as Suitable Additive for HILIC-Based LC-HRMS Metabolomics." Metabolites 9, no. 12 (2019): 292. http://dx.doi.org/10.3390/metabo9120292.

Full text

Abstract:

Hydrophilic Interaction Liquid Chromatography (HILIC) chromatography is widely applied in metabolomics as a complementary strategy to reverse phase chromatography. Nevertheless, it still faces several issues in terms of peak shape and compounds ionization, limiting the automatic de-convolution and data semi-quantification performed through dedicated software. A way to improve the chromatographic and ionization performance of a HILIC method is to modify the electrostatic interactions of the analytes with both mobile and stationary phases. In this study, using a ZIC-HILIC chromatographic phase, we evaluated the performance of ammonium fluoride (AF) as additive salt, comparing its performance to ammonium acetate (AA). Three comparative criteria were selected: (1) identification and peak quality of 34 standards following a metabolomics-specific evaluation approach, (2) an intraday repeatability test with real samples and (3) performing two real metabolomics fingerprints with the AF method to evaluate its inter-day repeatability. The AF method showed not only higher ionization efficiency and signal-to-noise ratio but also better repeatability and robustness than the AA approach. A tips and tricks section is then added, aiming at improving method replicability for further users. In conclusion, ammonium fluoride as additive salt presents several advantages and might be considered as a step forward in the application of robust HILIC methods in metabolomics.

APA, Harvard, Vancouver, ISO, and other styles

50

Vrobel, Ivo, David Friedecký, Edgar Faber, et al. "Novel sulphur-containing imatinib metabolites found by untargeted LC-HRMS analysis." European Journal of Pharmaceutical Sciences 104 (June 2017): 335–43. http://dx.doi.org/10.1016/j.ejps.2017.04.014.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Lc-hrms'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles