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Artículos de revistas sobre el tema "LC-MS methods"

Autor: Grafiati

Publicado: 10 de marzo de 2023

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1

Chikasou, Masato, Syuichi Inohana, Toshiaki Yokozeki, Hitoshi Tuchiya, and Kazuhiro Fujita. "Development of LC-MS and LC-MS/MS Methods for Free Asparagine in Grains." Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) 59, no. 5 (2018): 248–56. http://dx.doi.org/10.3358/shokueishi.59.248.

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2

Kobayashi, Hiroko. "Development of Residue Analysis for Pesticides by LC/MS and LC/MS/MS Methods." BUNSEKI KAGAKU 58, no. 12 (2009): 985–97. http://dx.doi.org/10.2116/bunsekikagaku.58.985.

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3

Viette, Véronique, Denis Hochstrasser, and Marc Fathi. "LC-MS (/MS) in Clinical Toxicology Screening Methods." CHIMIA International Journal for Chemistry 66, no. 5 (2012): 339–42. http://dx.doi.org/10.2533/chimia.2012.339.

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4

Deng, Pan, Yan Zhan, Xiaoyan Chen, and Dafang Zhong. "Derivatization methods for quantitative bioanalysis by LC–MS/MS." Bioanalysis 4, no. 1 (2012): 49–69. http://dx.doi.org/10.4155/bio.11.298.

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5

HAYASHI, Takako, and Kenji HAMASE. "Determination of Clenbuterol in Various Edible Parts of Livestock Products by LC-MS/MS and LC-MS/MS/MS Methods." CHROMATOGRAPHY 42, no. 1 (2021): 43–48. http://dx.doi.org/10.15583/jpchrom.2020.021.

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6

Duggan, Jeffrey, Bailuo Ren, Yan Mao, Lin-Zhi Chen, and Elsy Philip. "LC–MS quantification of protein drugs: validating protein LC–MS methods with predigestion immunocapture." Bioanalysis 8, no. 18 (2016): 1951–64. http://dx.doi.org/10.4155/bio-2016-0137.

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7

Downs, Melanie L., and Philip Johnson. "Target Selection Strategies for LC-MS/MS Food Allergen Methods." Journal of AOAC INTERNATIONAL 101, no. 1 (2018): 146–51. http://dx.doi.org/10.5740/jaoacint.17-0404.

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Abstract The detection and quantitation of allergens as contaminants in foods using MS is challenging largely due to the requirement to detect proteins in complex, mixed, and often processed matrixes. Such methods necessarily rely on the use of proteotypic peptides as indicators of the presence and amount of allergenic foods. These peptides should represent the allergenic food in question in such a way that their use is both sensitive (no false-negatives) and specific (no false-positives). Choosing such peptides to represent food allergens is beset with issues, including, but not limited to, separated ingredients (e.g., casein and whey), extraction difficulties (particularly from thermally processed foods), and incomplete sequence information, as well as the more common issues associated with protein quantitation in biological samples. Here, we review the workflows that have been used to select peptide targets for food allergen detection. We describe the use and limitations of both in silico-based analyses and experimental methods relying on high-resolution MS. The variation in the way in which target selection is performed highlights a lack of standardization, even around the principles describing what the detection method should achieve. A lack of focus on the food matrixes to which the method will be applied is also apparent during the peptide target selection process. It is hoped that highlighting some of these issues will assist in the generation of MS-based allergen detection methods that will encourage uptake and use by the analytical community at large.

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8

Lapko, Veniamin N., Patrick S. Miller, G. Paul Brown, et al. "Sensitive glucagon quantification by immunochemical and LC–MS/MS methods." Bioanalysis 5, no. 23 (2013): 2957–72. http://dx.doi.org/10.4155/bio.13.264.

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9

Vazvaei, Faye, and Jeffrey X. Duggan. "Validation of LC–MS/MS bioanalytical methods for protein therapeutics." Bioanalysis 6, no. 13 (2014): 1739–42. http://dx.doi.org/10.4155/bio.14.125.

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10

Naidong, Weng, Yu-Luan Chen, Wilson Shou, and Xiangyu Jiang. "Importance of injection solution composition for LC–MS–MS methods." Journal of Pharmaceutical and Biomedical Analysis 26, no. 5-6 (2001): 753–67. http://dx.doi.org/10.1016/s0731-7085(01)00439-3.

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11

Pascale, Michelangelo, Annalisa De Girolamo, Vincenzo Lippolis, Joerg Stroka, Hans G. J. Mol, and Veronica M. T. Lattanzio. "Performance Evaluation of LC-MS Methods for Multimycotoxin Determination." Journal of AOAC International 102, no. 6 (2019): 1708–20. http://dx.doi.org/10.5740/jaoacint.19-0068.

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The co-occurrence of regulated mycotoxins in foods and feeds, together with modified (“masked”) and emerging mycotoxins, has been increasingly reported worldwide in recent years. Therefore, sensitive, accurate, and validated methods for the simultaneous determination of these hazardous contaminants in different matrices are highly demanded to fulfil regulatory requirements and to carry out reliable surveillance programs. In these last years, LC-MS methodologies for multimycotoxin screening and/or quantification are being routinely used in control laboratories. However, to date, only one European Standard for multimycotoxin determination is based on LC-MS (EN 16877:2016). The need for standardized LC-MS methods for multimycotoxin determination has been highlighted by regulatory authorities and scientific advisory bodies, including the U.S. Food and Drug Administration and the European Commission. The European Committee for Standardization (CEN) has issued calls for tender for the development of standardized LC-MS methods for mycotoxins in food and animal feeding stuffs. As deliverables, some LC-MS based methods for multimycotoxin determination are currently under approval as European Standards. In addition, the European Commission has recently established specific criteria with which screening methods for mycotoxins, including LC-MS methods, have to comply for use for regulatory purposes. Validation procedures by single-laboratory and collaborative trials have been defined. This paper provides insights and advances on guidelines and tools for performance evaluation of LC-MS methods intended for quantitative determination and for semiquantitative screening of multimycotoxins. In particular, performance criteria set in the European Union and the United States are critically overviewed, and expectations, needs, and future challenges relevant to LC-MS methods for multimycotoxin determination are also discussed.

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12

Pascale, Michelangelo, Annalisa De Girolamo, Vincenzo Lippolis, Joerg Stroka, Hans G. J. Mol, and Veronica M. T. Lattanzio. "Performance Evaluation of LC-MS Methods for Multimycotoxin Determination." Journal of AOAC INTERNATIONAL 102, no. 6 (2019): 1708–20. http://dx.doi.org/10.1093/jaoac/102.6.1708.

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Abstract The co-occurrence of regulated mycotoxins in foods and feeds, together with modified (“masked”) and emerging mycotoxins, has been increasingly reported worldwide in recent years. Therefore, sensitive, accurate, and validated methods for the simultaneous determination of these hazardous contaminants in different matrices are highly demanded to fulfil regulatory requirements and to carry out reliable surveillance programs. In these last years, LC-MS methodologies for multimycotoxin screening and/or quantification are being routinely used in control laboratories. However, to date, only one European Standard for multimycotoxin determination is based on LC-MS (EN 16877:2016). The need for standardized LC-MS methods for multimycotoxin determination has been highlighted by regulatory authorities and scientific advisory bodies, including the U.S. Food and Drug Administration and the European Commission. The European Committee for Standardization (CEN) has issued calls for tender for the development of standardized LC-MS methods for mycotoxins in food and animal feeding stuffs. As deliverables, some LC-MS based methods for multimycotoxin determination are currently under approval as European Standards. In addition, the European Commission has recently established specific criteria with which screening methods for mycotoxins, including LC-MS methods, have to comply for use for regulatory purposes. Validation procedures by single-laboratory and collaborative trials have been defined. This paper provides insights and advances on guidelines and tools for performance evaluation of LC-MS methods intended for quantitative determination and for semiquantitative screening of multimycotoxins. In particular, performance criteria set in the European Union and the United States are critically overviewed, and expectations, needs, and future challenges relevant to LC-MS methods for multimycotoxin determination are also discussed.

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13

Wong, Andrea, Xiaoqiang Xiang, Pei Ong, et al. "A Review on Liquid Chromatography-Tandem Mass Spectrometry Methods for Rapid Quantification of Oncology Drugs." Pharmaceutics 10, no. 4 (2018): 221. http://dx.doi.org/10.3390/pharmaceutics10040221.

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In the last decade, the tremendous improvement in the sensitivity and also affordability of liquid chromatography-tandem mass spectrometry (LC-MS/MS) has revolutionized its application in pharmaceutical analysis, resulting in widespread employment of LC-MS/MS in determining pharmaceutical compounds, including anticancer drugs in pharmaceutical research and also industries. Currently, LC-MS/MS has been widely used to quantify small molecule oncology drugs in various biological matrices to support preclinical and clinical pharmacokinetic studies in R&D of oncology drugs. This mini-review article will describe the state-of-the-art LC-MS/MS and its application in rapid quantification of small molecule anticancer drugs. In addition, efforts have also been made in this review to address several key aspects in the development of rapid LC-MS/MS methods, including sample preparation, chromatographic separation, and matrix effect evaluation.

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14

Zelzer, Sieglinde, Caroline Le Goff, Stéphanie Peeters, et al. "Comparison of two LC-MS/MS methods for the quantification of 24,25-dihydroxyvitamin D3 in patients and external quality assurance samples." Clinical Chemistry and Laboratory Medicine (CCLM) 60, no. 1 (2021): 74–81. http://dx.doi.org/10.1515/cclm-2021-0792.

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Abstract Objectives In-house developed liquid-chromatography mass spectrometry (LC-MS/MS) methods are used more and more frequently for the simultaneous quantification of vitamin D metabolites. Among these, 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) is of clinical interest. This study assessed the agreement of this metabolite in two validated in-house LC-MS/MS methods. Methods 24,25(OH)2D3 was measured in 20 samples from the vitamin D external quality assurance (DEQAS) program and in a mixed cohort of hospital patients samples (n=195) with the LC-MS/MS method at the Medical University of Graz (LC-MS/MS 1) and at the University of Liège (LC-MS/MS 2). Results In DEQAS samples, 24,25(OH)2D3 results with LC-MS/MS 1 had a proportional bias of 1.0% and a negative systemic difference of −0.05%. LC-MS/MS 2 also showed a proportional bias of 1.0% and the negative systemic bias was −0.22%. Comparing the EQA samples with both methods, no systemic bias was found (0.0%) and the slope was 1%. The mean difference of 195 serum sample measurements between the two LC-MS/MS methods was minimal (−0.2%). Both LC-MS/MS methods showed a constant bias of 0.31 nmol/L and a positive proportional bias of 0.90%, respectively. Conclusions This study is the first to assess the comparability of 24,25(OH)2D3 concentrations in a mixed cohort of hospitalized patients with two fully validated in-house LC-MS/MS methods. Despite different sample preparation, chromatographic separation and ionization, both methods showed high precision measurements of 24,25(OH)2D3. Furthermore, we demonstrate the improvement of accuracy and precision measurements of 24,25(OH)2D3 in serum samples and in the DEQAS program.

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15

Lee, Ji Hyun, Han Na Park, Hyoung-Joon Park, et al. "Development and Validation of LC–MS/MS and LC-Q-Orbitrap/MS Methods for Determination of Glyphosate in Vaccines." Chromatographia 80, no. 12 (2017): 1741–47. http://dx.doi.org/10.1007/s10337-017-3417-9.

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16

Tokumura, Masahiro, Yuichi Miyake, Qi Wang, et al. "Methods for the analysis of organophosphorus flame retardants—Comparison of GC-EI-MS, GC-NCI-MS, LC-ESI-MS/MS, and LC-APCI-MS/MS." Journal of Environmental Science and Health, Part A 53, no. 5 (2018): 475–81. http://dx.doi.org/10.1080/10934529.2017.1410419.

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17

Obeid, Rima, Jürgen Geisel, and Wolfgang Herrmann. "Comparison of two methods for measuring methylmalonic acid as a marker for vitamin B12 deficiency." Diagnosis 2, no. 1 (2015): 67–72. http://dx.doi.org/10.1515/dx-2014-0030.

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AbstractMethylmalonic acid (MMA) is a functional marker of vitamin B12 status and a valuable diagnostic tool. The gas chromatography mass spectrometry (GCMS) MMA assay has been used for decades in clinical studies.In this study, we compared a newly developed liquid chromatography tandem mass spectrometry assay for MMA (ClinMassThe GCMS and LC-MS/MS assays showed a strong correlation (r=0.92, p<0.001) particularly at low holoTC levels (deficiency is more probable). Forty six cases had MMA>300 nmol/L with both methods. Only five subjects showed MMA GCMS>300 nmol/L, but MMA LC-MS/MS≤300 nmol/L. However, the LC-MS/MS method showed a slightly better correlation with other B12 markers (holoTC, total B12). In addition, the LC-MS/MS method offers several advantages over the GCMS method, such as saving time and costs, precision, flexibility and popularity in modern labs.The new LC-MS/MS assay for MMA showed an excellent correlation to the GCMS method. The two methods showed similar agreements with other vitamin B12 markers.

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18

HESS, P., E. MCGOVERN, T. MCMAHON, et al. "LC-UV and LC-MS methods for the determination of domoic acid." TrAC Trends in Analytical Chemistry 24, no. 4 (2005): 358–67. http://dx.doi.org/10.1016/j.trac.2004.11.019.

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19

Sharma, Kuldeep, and Ramesh Mullangi. "A concise review of HPLC, LC-MS and LC-MS/MS methods for determination of azithromycin in various biological matrices." Biomedical Chromatography 27, no. 10 (2013): 1243–58. http://dx.doi.org/10.1002/bmc.2898.

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20

Al-Neaimy, Usra Ibrahim Saeed, Zainab Faiyq Saeed, and Sahar Mahmood Shehab. "A Review on Analytical Methods for Piperazine Determination." NTU Journal of Pure Sciences 1, no. 3 (2022): 1–9. http://dx.doi.org/10.56286/ntujps.v1i3.230.

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Piperazine compounds mediate their anthelmintic action by generally paralyzing parasites, allowing the host body to easily remove or expel the invading organism. It is an anthelmintic drug in human as well as in veterinary medicine. This review article represent the various analytical methods which has been reported for estimation of piperazine. The colorimetric , spectrophotometric techniques and chromatographic methods like HPLC and RP HPLC, GC, LC-MS, LC-MS/MS and another methods were reported.

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21

Mahabee-Gittens, E. Melinda, Matthew J. Mazzella, John T. Doucette, et al. "Comparison of Liquid Chromatography Mass Spectrometry and Enzyme-Linked Immunosorbent Assay Methods to Measure Salivary Cotinine Levels in Ill Children." International Journal of Environmental Research and Public Health 17, no. 4 (2020): 1157. http://dx.doi.org/10.3390/ijerph17041157.

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Objective: Cotinine is the preferred biomarker to validate levels of tobacco smoke exposure (TSE) in children. Compared to enzyme-linked immunosorbent assay methods (ELISA) for quantifying cotinine in saliva, the use of liquid chromatography tandem mass spectrometry (LC-MS/MS) has higher sensitivity and specificity to measure very low levels of TSE. We sought to compare LC-MS/MS and ELISA measures of cotinine in saliva samples from children overall and the associations of these measures with demographics and TSE patterns. Method: Participants were nonsmoking children (N = 218; age mean (SD) = 6.1 (5.1) years) presenting to a pediatric emergency department. Saliva samples were analyzed for cotinine using both LC-MS/MS and ELISA. Limit of quantitation (LOQ) for LC-MS/MS and ELISA was 0.1 ng/mL and 0.15 ng/mL, respectively. Results: Intraclass correlations (ICC) across methods = 0.884 and was consistent in sex and age subgroups. The geometric mean (GeoM) of LC-MS/MS = 4.1 (range: < LOQ to 382 ng/mL; 3% < LOQ) which was lower (p < 0.0001) than the ELISA GeoM = 5.7 (range: < LOQ to 364 ng/mL; 5% < LOQ). Similar associations of cotinine concentrations with age ( β ^ < −0.10, p < 0.0001), demographic characteristics (e.g., income), and number of cigarettes smoked by caregiver ( β ^ > 0.07, p < 0.0001) were found regardless of cotinine detection method; however, cotinine associations with sex and race/ethnicity were only found to be significant in models using LC-MS/MS-derived cotinine. Conclusions: Utilizing LC-MS/MS-based cotinine, associations of cotinine with sex and race/ethnicity of child were revealed that were not detectable using ELISA-based cotinine, demonstrating the benefits of utilizing the more sensitive LC-MS/MS assay for cotinine measurement when detecting low levels of TSE in children.

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22

Yun, Jisuk, Jinyoung Kim, Jangduck Choi, Kisung Kwon, and Cheon-Ho Jo. "Simultaneous determination of Phlomis umbrosa and Dipsacus asperoides in foods using LC-MS/MS methods." Korean Journal of Food Science and Technology 48, no. 6 (2016): 531–35. http://dx.doi.org/10.9721/kjfst.2016.48.6.531.

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23

HIRAOKA, Kenzo. "Development of New Ionization Methods for GC/MS and LC/MS Interfaces." Journal of the Mass Spectrometry Society of Japan 53, no. 2 (2005): 60–78. http://dx.doi.org/10.5702/massspec.53.60.

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24

Nel, Andrew J. M., Shaun Garnett, Jonathan M. Blackburn, and Nelson C. Soares. "Comparative Reevaluation of FASP and Enhanced FASP Methods by LC–MS/MS." Journal of Proteome Research 14, no. 3 (2015): 1637–42. http://dx.doi.org/10.1021/pr501266c.

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25

Heath, D. D., S. W. Flatt, A. H. B. Wu, M. A. Pruitt, and C. L. Rock. "Evaluation of Tamoxifen and Metabolites by LC-MS/MS and HPLC Methods." British Journal of Biomedical Science 71, no. 1 (2014): 33–39. http://dx.doi.org/10.1080/09674845.2014.11669960.

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26

W, Brown N., Gonde C. E, Adams J. E, and Tredger J. M. "The Clinical Advantages of LC-MS/MS Over Meia Methods for Tacrolimus." Therapeutic Drug Monitoring 27, no. 2 (2005): 214. http://dx.doi.org/10.1097/00007691-200504000-00030.

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27

Jenkins, Rand, Jeffrey X. Duggan, Anne-Françoise Aubry, et al. "Recommendations for Validation of LC-MS/MS Bioanalytical Methods for Protein Biotherapeutics." AAPS Journal 17, no. 1 (2014): 1–16. http://dx.doi.org/10.1208/s12248-014-9685-5.

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28

Wang, J., D. Yan, A. Zhao, et al. "Discovery of potential biomarkers for osteoporosis using LC-MS/MS metabolomic methods." Osteoporosis International 30, no. 7 (2019): 1491–99. http://dx.doi.org/10.1007/s00198-019-04892-0.

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29

Lim, Chee Wei, Gerald Chung, and Sheot Harn Chan. "Analytical Methods for Mycotoxin Detection in Southeast Asian Nations (ASEAN)." Journal of AOAC INTERNATIONAL 101, no. 3 (2018): 613–17. http://dx.doi.org/10.5740/jaoacint.17-0335.

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Abstract Aflatoxins B1 (AFB1) and B2 (AFB2) and G1 and G2 remain the top mycotoxins routinely analyzed and monitored by Association of Southeast Asian Nations (ASEAN) national laboratories primarily for food safety regulation in the major food commodities, nuts and spices. LC tandem fluorescence detection (LC–fluorescence) represents a current mainstream analytical method, with a progressive migration to a primary method by LC tandem MS (MS/MS) for the next half decade. Annual proficiency testing (PT) is conducted by ASEAN Food Reference Laboratories (AFRLs) for mycotoxin testing as part of capability building in national laboratories, with the scope of PT materials spanning from naturally mycotoxin-contaminated spices and nuts in the early 2010s to the recent contamination of corn flour in 2017 for total aflatoxin assay development. The merits of the mainstream LC–fluorescence method are witnessed by a significant improvement (P &lt; 0.05) in PT z-score passing rates (≤2) from 11.8 to 79.2% for AFB1, 23.5 to 83.3% for AFB2, and 23.5 to 79.2% for total aflatoxins in the last 5 years. This paper discusses the journey of ASEAN national laboratories in analytical testing through AFRLs, and the progressive collective adoption of a multimycotoxin LC-MS/MS method aided by an isotopic dilution assay as a future primary method for safer food commodities.

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30

Babić, Nikolina. "Analytical methods and performance of the immunoassay methods for determination of vitamin d in comparison to mass spectrometry / Analitičke metode i izvođenje imunometrijskih određivanja vitamina d u poređenju sa masenom spektrometrijom." Journal of Medical Biochemistry 31, no. 4 (2012): 333–38. http://dx.doi.org/10.2478/v10011-012-0022-1.

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Summary Demand for vitamin D testing has been on a constant rise worldwide, partially due to mounting evidence linking vitamin D status to overall health and well-being. Currently available assays measure 25-hydroxy vitamin D (25-OHD), a major circulating form of vitamin D. Available methodologies include immunoassays and mass spectrometry based methods (LC-MS/MS). Until recently, the only immunoassays available for diagnostic use in the US have been DiaSorin radioimmunoassay (RIA) and an automated immunoassay on a LIAISON® platform. Within the last year, Siemens and Abbott successfully launched immuno - assays for determination of total vitamin D on their respective automated platforms, Centaur® and ARCHITECT®. Development of robust and precise Vitamin D immunoassays has historically been plagued with difficulty. One of the major challenges is development of specific antibodies against such a small antigen. Vitamin D is also highly hy - drophobic molecule predominantly bound to vitamin D binding protein (DBP). It is likely, therefore, that immuno - assays might be affected to varying extent by the DBP concentration. Adoption of LC-MS/MS into clinical laboratories has enabled development of accurate and almost fully automated methods that could handle increasing volume demands, especially in large volume reference laboratories. Smaller to mid-size hospital laboratories as well as physician offices have neither funds nor technical expertise to implement LC-MS/MS based testing. Our laboratory at the University of Chicago Medical Center has also seen in - crease in vitamin D volume and currently performs close to 20,000 25-OHD assays per year. We have recently deve - loped an LC-MS/MS method for quantitation of 25-OHD2 (obtained from plant sources) and 25-OHD3 (endogenous and animal sources). Prior to acquisition of LC-MS/MS instrument, we performed 25-OHD analysis by RIA. Du - ring the transition period, we encountered several challenges, including the necessity to streamline sample preparation as well as the bias introduced by calibration dif ferences. We chose to match our LC-MS/MS method to the RIA method in order to make this transition transparent to the clinician. Most immunoassays available today are acceptable for clinical use and might be method of choice for smaller laboratories. Larger clinical laboratories and aca demic institutions that possess technical expertise, particularly the ones with large pediatric population where assay sensitivity and specificity may be important, might find LC-MS/MS methodology a more suitable choice.

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31

Mellon, Fred A., Richard N. Bennett, Birgit Holst, and Gary Williamson. "Intact Glucosinolate Analysis in Plant Extracts by Programmed Cone Voltage Electrospray LC/MS: Performance and Comparison with LC/MS/MS Methods." Analytical Biochemistry 306, no. 1 (2002): 83–91. http://dx.doi.org/10.1006/abio.2002.5677.

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32

Sherma, Joseph. "High-Performance Liquid Chromatography/Mass Spectrometry Analysis of Botanical Medicines and Dietary Supplements: A Review." Journal of AOAC INTERNATIONAL 86, no. 5 (2003): 873–81. http://dx.doi.org/10.1093/jaoac/86.5.873.

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Abstract This article reviews research on the qualitative and quantitative analysis by high-performance column liquid chromatography/mass spectrometry (LC/MS) and LC/tandem mass spectrometry (LC/MS/MS) of botanical drugs, drug substances or preparations, and finished botanical products. In addition, LC/MS and LC/MS/MS techniques and commercial instruments are described and compared briefly, and prospects for future use of these methods for the analysis of botanicals are suggested. Some applications of direct MS without LC are also described.

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33

Malesevic, M., L. Zivanovic, A. Protic, et al. "Stress degradation studies on zolpidem tartrate using LC-DAD and LC-MS methods." Acta Chromatographica 26, no. 1 (2014): 81–96. http://dx.doi.org/10.1556/achrom.26.2014.1.8.

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34

Sun, Yuchen, Shin-ichiro Nitta, Kosuke Saito, et al. "Development and multicenter validation of an LC–MS-based bioanalytical method for antisense therapeutics." Bioanalysis 14, no. 18 (2022): 1213–27. http://dx.doi.org/10.4155/bio-2022-0126.

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Background: Many bioanalytical methods for antisense oligonucleotides (ASOs) using LC–MS have been reported. However, no data have been available on the reproducibility and robustness of a single bioanalytical method for ASOs. As such, in the current study, we evaluated the reproducibility and robustness of LC–MS-based bioanalytical methods for ASOs in multiple laboratories. Methods/Results: Seven independent laboratories were included in this study. Mipomersen was measured by ion-pairing LC–MS (IP-LC–MS) as a model ASO using different LC–MS. The validation results of calibration curve, accuracy, precision and selectivity met the criteria of conventional bioanalytical method validation guidelines using LC/GC–MS for drugs in all laboratories. Meanwhile, carryover (>20%) was detected in three laboratories. Conclusion: We first demonstrated the multicenter-validated IP-LC–MS bioanalytical method for ASOs. Our data showed that the method was sensitive, robust and reproducible. However, the occurrence of carryover should be carefully monitored in its future application.

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Gill, Brendon D., Harvey E. Indyk, Tadashi Kobayashi, Iain J. McGrail, and David C. Woollard. "Comparison of LC-MS/MS and Enzymatic Methods for the Determination of Total Choline and Total Carnitine in Infant Formula and Milk Products." Journal of AOAC INTERNATIONAL 103, no. 5 (2020): 1293–300. http://dx.doi.org/10.1093/jaoacint/qsaa060.

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Abstract Background Choline and l-carnitine are classified as pseudo-vitamins because of their conditionally essential status. As they are involved in multiple physiological metabolic pathways in the human body, they are routinely fortified in infant and adult nutritional formulas. Objective The performance of an LC-MS/MS method for the analysis of choline and carnitine, compared with enzymatic methods in routine use for the analysis of total carnitine and total choline, is described. Method Powder samples were reconstituted, with release of carnitine and choline facilitated by both acid and alkaline hydrolysis and the extract analyzed by LC-MS/MS. Quantitation was by internal standard technique using deuterium-labeled carnitine and deuterium-labeled choline. Results Method range, specificity, sensitivity, precision, recovery, accuracy, and ruggedness were assessed for milk powders, infant formulas, and soy- and milk-based nutritional products. Spike recoveries of 94.0–108.4% were obtained for both total carnitine and choline, and no statistical bias (α = 0.05) between measured results and certified values (choline: P = 0.36; free carnitine: P = 0.67) was found for NIST 1849a certified reference material (NIST1849a). Precision, as repeatability relative standard deviation (RSD), was 2.0% RSDr for total carnitine and 1.7% RSDr for total choline. Equivalent results for total choline and total carnitine were obtained by LC-MS/MS and enzymatic methods (n = 30). Conclusions The described LC-MS/MS method is fit for purpose for routine product compliance release testing environments. This validation study has confirmed that alternative enzymatic assays can be used with confidence in laboratories in which LC-MS/MS platforms are unavailable. Highlights An LC-MS/MS method was evaluated and found to be fit-for-purpose for routine product compliance release testing of infant formula. The LC-MS/MS method was compared with enzymatic methods for the analysis of total carnitine and total choline. Alternative enzymatic assays can be used with confidence in laboratories in which LC-MS/MS platforms are unavailable.

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Zhu, Yunting, Pan Deng, and Dafang Zhong. "Derivatization methods for LC–MS analysis of endogenous compounds." Bioanalysis 7, no. 19 (2015): 2557–81. http://dx.doi.org/10.4155/bio.15.183.

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Zhang, Kai. "Comparison of Flow Injection-MS/MS and LC-MS/MS for the Determination of Ochratoxin A." Toxins 13, no. 8 (2021): 547. http://dx.doi.org/10.3390/toxins13080547.

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Two methods for measuring ochratoxin A in corn, oat, and grape juice were developed and compared. Flow injection (FI) and on-line liquid chromatography (LC) performances were evaluated separately, with both methods using a triple quadrupole tandem mass spectrometer (MS/MS) for quantitation. Samples were fortified with 13C uniformly labeled ochratoxin A as the internal standard (13C-IS) and prepared by dilution and filtration, followed by FI- and LC-MS/MS analysis. For the LC-MS/MS method, which had a 10 min run time/sample, recoveries of ochratoxin A fortified at 1, 5, 20, and 100 ppb in corn, oat, red grape juice, and white grape juice ranged from 100% to 117% with RSDs < 9%. The analysis time of the FI-MS/MS method was <60 s/sample, however, the method could not detect ochratoxin A at the lowest fortification concentration, 1 ppb, in all tested matrix sources. At 5, 20, and 100 ppb, recoveries by FI-MS/MS ranged from 79 to 117% with RSDs < 15%. The FI-MS/MS method also had ~5× higher solvent and matrix-dependent instrument detection limits (0.12–0.35 ppb) compared to the LC-MS/MS method (0.02–0.06 ppb). In the analysis of incurred corn and oat samples, both methods generated comparable results within ±20% of reference values, however, the FI-MS/MS method failed to determine ochratoxin A in two incurred wheat flour samples due to co-eluted interferences due to the lack of chromatographic separation.

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Büttler, Rahel M., Frans Martens, Flaminia Fanelli, et al. "Comparison of 7 Published LC-MS/MS Methods for the Simultaneous Measurement of Testosterone, Androstenedione, and Dehydroepiandrosterone in Serum." Clinical Chemistry 61, no. 12 (2015): 1475–83. http://dx.doi.org/10.1373/clinchem.2015.242859.

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Abstract BACKGROUND Recently, LC-MS/MS was stated to be the method of choice to measure sex steroids. Because information on the mutual agreement of LC-MS/MS methods is scarce, we compared 7 published LC-MS/MS methods for the simultaneous measurement of testosterone, androstenedione, and dehydroepiandrosterone (DHEA). METHODS We used 7 published LC-MS/MS methods to analyze in duplicate 55 random samples from both men and women. We performed Passing–Bablok regression analysis and calculated Pearson correlation coefficients to assess the agreement of the methods investigated with the median concentration measured by all methods, and we calculated the intraassay CV of each method derived from duplicate results and the CVs between the methods. RESULTS Median concentrations of testosterone were 0.22–1.36 nmol/L for women and 8.27–27.98 nmol/L for men. Androstenedione and DHEA concentrations were 0.05–5.53 and 0.58–18.04 nmol/L, respectively. Intraassay CVs were 2.9%–10%, 1.2%–8.8%, 2.7%–13%, and 4.3%–16% for testosterone in women, testosterone in men, androstenedione, and DHEA. Slopes of the regression lines calculated by Passing–Bablok regression analysis were 0.92–1.08, 0.92–1.08, 0.90–1.13, and 0.91–1.41 for all testosterone values, testosterone in women, androstenedione, and DHEA. Intermethod CVs were 14%, 8%, 30%, and 22% for testosterone in women, testosterone in men, androstenedione, and DHEA. CONCLUSIONS In general, the LC-MS/MS methods investigated show reasonable agreement. However, some of the assays show differences in standardization, and others show high variation.

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Vogeser, Michael, and Christoph Seger. "Pitfalls Associated with the Use of Liquid Chromatography–Tandem Mass Spectrometry in the Clinical Laboratory." Clinical Chemistry 56, no. 8 (2010): 1234–44. http://dx.doi.org/10.1373/clinchem.2009.138602.

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BACKGROUND Novel mass spectrometric techniques such as atmospheric pressure ionization and tandem mass spectrometry have substantially extended the spectrum of clinical chemistry methods during the past decade. In particular, liquid chromatography tandem–mass spectrometry (LC-MS/MS) has become a standard tool in research laboratories as well as in many clinical laboratories. Although LC-MS/MS has features that suggest it has a very high analytical accuracy, potential sources of inaccuracy have recently been identified. CONTENT The sources of inaccuracy in LC-MS/MS methods used in the routine quantification of small molecules are described and discussed. Inaccuracy of LC-MS/MS methods can be related to the process of ionization through the insource transformation of conjugate metabolites or target analytes and may also be attributable to ionization matrix effects that have a differential impact on target analytes and internal-standard compounds. Inaccuracy can also be associated with the process of ion selection, which mainly occurs when compounds from the sample matrix share mass transitions with a target analyte. In individual assays, most potential sources of inaccuracy can be controlled by sufficient LC separation–based sample workup before MS analysis. SUMMARY LC-MS/MS methods should undergo rigorous and systematic validation before introduction into patient care.

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Kellie, John F. "Intact protein LC–MS for pharmacokinetics." International Journal of Pharmacokinetics 4, no. 4 (2019): IPK05. http://dx.doi.org/10.4155/ipk-2020-0004.

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Biography: John Kellie is currently a GlaxoSmithKline (GSK) fellow in the Bioanalysis, Immunogenicity, and Biomarkers group at GSK. John received his B.Sc. in Biochemistry from Indiana University (USA) and his PhD in Chemistry from Northwestern University (USA) studying under Dr Neil Kelleher. He was a post-doctoral scientist at Eli Lilly and Company, where he developed methods for intact protein quantitation of a Parkinson’s Disease biomarker from human brain tissue. At GSK, John utilizes mass spectrometry for development of novel bioanalytical methods for biotherapeutic and protein quantitation from pre-clinical and clinical samples, with a focus on intact protein and large mass quantitation for pharmacokinetics, catabolism, biotransformation and product quality attribute support. John Kellie speaks to the International Journal of Pharmacokinetics about intact protein LC–MS for pharmacokinetic application.

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Kushnir, Mark M., Alan L. Rockwood, Frederick G. Strathmann, Elizabeth L. Frank, Joely A. Straseski, and A. Wayne Meikle. "LC-MS/MS Measurement of Parathyroid Hormone–Related Peptide." Clinical Chemistry 62, no. 1 (2016): 218–26. http://dx.doi.org/10.1373/clinchem.2015.244012.

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Abstract INTRODUCTION Parathyroid hormone–related peptide (PTHrP) is involved in activating pathways, allowing tumor cells to form bone metastases. Measurement of PTHrP is used for the diagnosis and clinical management of patients suspected of hypercalcemia of malignancy. We developed an LC-MS/MS method for measuring PTHrP, established sex-specific reference intervals, and assessed the method's performance. METHODS PTHrP was enriched from plasma samples with rabbit polyclonal anti-PTHrP antibody conjugated to magnetic beads. Enriched PTHrP was digested with trypsin, and PTHrP-specific tryptic peptide was analyzed with 2-dimensional LC-MS/MS in multiple reaction monitoring mode. RESULTS The lower limit of quantification was 0.6 pmol/L, and the upper limit of linearity was 600 pmol/L. Total imprecision was &lt;10%. Very poor agreement was observed with the RIA (n = 207; Deming regression RIA = 0.059 × LC-MS/MS − 1.8, r = 0.483; Sy|x = 3.9). Evaluation of the clinical performance of the assay using samples from patients with and without hypercalcemia (n = 199) resulted in an area under the ROC curve of 0.874. In sets of consecutively analyzed routine samples of patients assessed for hypercalcemia, the PTHrP positivity rate by RIA (n = 1376) was 1.9%, and 26.6% by LC-MS/MS (n = 1705). Concentrations were below the lower limit of quantification in 95.6% of the samples by RIA and 2.0% by LC-MS/MS. CONCLUSIONS PTHrP is a normal constituent in circulating blood and its concentrations are substantially underestimated by commercial RIAs, causing false-negative results in samples from patients suspected of hypercalcemia. Our observations suggest a link between increased concentrations of PTHrP in postmenopausal women with low body mass index and increased incidence of osteoporosis.

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Huddleston, Michael J., Mark F. Bean, and Steven A. Carr. "Collisional fragmentation of glycopeptides by electrospray ionization LC/MS and LC/MS/MS: methods for selective detection of glycopeptides in protein digests." Analytical Chemistry 65, no. 7 (1993): 877–84. http://dx.doi.org/10.1021/ac00055a009.

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Xie, Li-Qi, Cheng-Pin Shen, Min-Bo Liu, et al. "Improved proteomic analysis pipeline for LC-ETD-MS/MS using charge enhancing methods." Molecular BioSystems 8, no. 10 (2012): 2692. http://dx.doi.org/10.1039/c2mb25106j.

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Briem, S., E. Eklund, G. Williams, and J. Brunvoll. "Comparison of three methods for pharmacokinetic screening in rats using LC-MS-MS." Chromatographia 55, S1 (2002): S35—S39. http://dx.doi.org/10.1007/bf02493350.

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Keevil, Brian G. "Novel liquid chromatography tandem mass spectrometry (LC-MS/MS) methods for measuring steroids." Best Practice & Research Clinical Endocrinology & Metabolism 27, no. 5 (2013): 663–74. http://dx.doi.org/10.1016/j.beem.2013.05.015.

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Negre, Michèle, Iride Passarella, Daniela Vindrola, and Andrea Baglieri. "Determination of Forchlorfenuron in Fruits by Solid Phase or QuEChERS Extraction and LC-UV or LC/MS/MS." Journal of AOAC INTERNATIONAL 97, no. 3 (2014): 938–41. http://dx.doi.org/10.5740/jaoacint.13-064.

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Abstract Forchlorfenuron, N-(2-chloro-4-pyridinyl)-N′-phenylurea, is a plant growth regulator used to increase the size of kiwifruit, apples, table grapes, and peaches and to promote increased yields of potatoes, rice, and wheat. This study reports the comparison of the performancesof two extraction methods [Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) and SPE] and two analytical methods (LC-UV and a LC/MS/MS) when determining forchlorfenuron in apples, kiwis, and grapes. Both extraction methods gave recoveries of forchlorfenuron from fruits &gt;70%. The QuEChERS method was cheaper, safer, and less time-consuming than the SPE method and can be recommended for routine analysis. The LOQ was 2 and 10 μg/kg for the LC/MS/MS and LC-UV analysis, respectively. The LOD was 1 and 5 μg/kg for the LC/MS/MS and LC-UV analysis, respectively. The sensitivity of the LC-UV analysis was adequate to measure residue levels five times lower than the maximum residue limit (MRL) of the product. The QuEChERS and SPE methods were applied to monitoring the persistence of forchlorfenuron in field-treated kiwis, and it was found that the residual concentration was already much lower than the MRL 7 days after treatment.

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Sinha, Sandipan, Gary Pipes, Elizabeth M. Topp, Pavel V. Bondarenko, Michael J. Treuheit, and Himanshu S. Gadgil. "Comparison of LC and LC/MS methods for quantifying N-glycosylation in recombinant IgGs." Journal of the American Society for Mass Spectrometry 19, no. 11 (2008): 1643–54. http://dx.doi.org/10.1016/j.jasms.2008.07.004.

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Castellani, Federica, Arianna Antonucci, Ivano Pindinello, Carmela Protano, and Matteo Vitali. "Determination of Carbonyl Compounds in Different Work Environments: Comparison between LC-UV/DAD and LC–MS/MS Detection Methods." International Journal of Environmental Research and Public Health 19, no. 19 (2022): 12052. http://dx.doi.org/10.3390/ijerph191912052.

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There were two analytical methods for the determination of 12 carbonyl compounds (CCs) by using liquid chromatography (LC) coupled with mass spectrometry (MS/MS) and diode array detector (UV/DAD) that were developed and applied to 52 samples that were collected in 10 workplaces. Linearity (0.996 < R2 < 0.999), intra-day repeatability (0.7 < RSD% < 10), and inter-day repeatability (5 < RSD% < 16) were acceptable for both techniques, but the highest sensibility of the MS/MS method allowed us to correctly quantify 98% of the samples (versus 32% by UV/DAD). The comparison of the concentrations that were obtained by quantifying the same sample with both techniques showed good agreement for acetaldehyde and formaldehyde (0.1 < % deviation < 30) but much higher for the less abundant congeners. In real samples, formaldehyde was the most abundant congener (concentrations between 2.7 and 77 µg m−3), followed by acetaldehyde (concentrations between 1.5 and 79 µg m−3) and butyraldehyde (concentrations between 0.4 and 13 µg m−3). In all the beauty salon samples, instead, the most abundant congener was acetaldehyde (concentrations between 19 and 79 µg m−3), probably associated with the use of beauty products. Principal components analysis (PCA) confirms the ubiquitous character of formaldehyde and highlights the influence of minority CCs on different workplaces.

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McCulloch, Melissa, and Yan Xu. "Quantitative Determination of Cannabinoid Receptor Antagonist Surinabant in Human Plasma by LC-UV and LC-ESI-MS/MS Methods." Journal of Liquid Chromatography & Related Technologies 32, no. 16 (2009): 2424–36. http://dx.doi.org/10.1080/10826070903188179.

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Sharma, Hemraj, Hari Prasad Sapkota, and Nim Bahadur Dangi. "A Brief Review of Analytical Methods for the Estimation of Allopurinol in Pharmaceutical Formulation and Biological Matrices." International Journal of Analytical Chemistry 2021 (June 5, 2021): 1–12. http://dx.doi.org/10.1155/2021/5558651.

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This review article represents the collection and discussion of various analytical methods available in the literature for the determination of allopurinol (ALLP) in pharmaceutical and biological samples consisting of HPLC, UV-visible method, near-IR spectroscopy, spectrofluorometry, capillary electrophoresis, polarography, voltammetry, and hyphenated techniques such as LC-MS, LC-MS/MS, UPLC-MS/MS, and GC-MS. The anticipated review provides details about the comparative utilization of various analytical techniques for the determination of ALLP. The present review article can be effectively explored to conduct future analytical investigation for the estimation of ALLP.

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