Academic literature on the topic 'Spectrophotometric detection with diode matrix (DAD)'

Representatives of the genus Bupleurum L. in the composition of biologically active substances accumulate triterpene compounds (derivatives of α-amyrin and β-amyrin). Triterpene glycosides isolated from plants of the genus Bupleurum are called saikosaponinov, buplevrozidy, skorzonerozidy. Plants of the genus Bupleurum in the underground organs accumulate triterpene compounds in an amount of from 1 to 7%. Triterpene compounds of plants of the genus Bupleurum possess a hepatoprotective, antiviral, cytostatic effect. We have studied the triterpene compounds of the aerial organs of Bupleurum scorzonerifolium Willd. The material for the study was collected on the territory of the Irkutsk region (Russia). Isolation of triterpene compounds was performed with 70% ethyl alcohol. The compounds were identified by liquid chromatography with mass spectrometry and diode-matrix detection (UPLC-DAD-ESI-MS/MS). According to the results of the analysis, the content of 5 triterpene compounds was established: saikosaponinov A, B2, C, D, F. The isolated compounds are structurally derived from oleanan, in which glycosidation is observed at the C-3 position with α-L-rhinose, β-D-glucose and β-D-fucose. The spectrophotometric method determined the quantitative content of the amount of triterpene compounds in the above-ground organs of B. scorzonerifolium at different phases of the vegetation of the plant, by organs (in flowers, leaves, stalks), and also depending on the place of growth. It has been established that the maximum amount of the amount of triterpene compounds accumulates in the aboveground organs of B. scorzonerifolium during the flowering phase – 1.54±0.05%; the highest content of this group of compounds is noted in flowers – 1.70±0.06%; most of all, this group of compounds is collected by samples collected in the Ust-Horde Buryat District (1.96±0.06%). The aboveground organs of B. scorzonerifolium can be used as a source of triterpene compounds, the highest content of which is noted in the flowering phase. The study of triterpene compounds in the aboveground organs of B. scorzonerifolium was carried out for the first time.

Comparison of column-coupled electrophoresis with liquid chromatography methods in food analysis of quinineComparison of column-coupled electrophoresis with liquid chromatography methods in food analysis of quinine (QUI) is presented in this work. The capillary isotachophoresis (CITP) on-line coupled with capillary zone electrophoresis (CZE) and hyphenated with fibre-based spectrophotometric diode array detection (DAD) was compared with, (i) high performance liquid chromatography (HPLC) method with DAD detection, and (ii) HPLC method with fluorescence detection (FD). These methods were compared through their performance parameters and determined concentrations of QUI in beverages. The concentrations of QUI in two selected bitter drinks determined by the CITP-CZE-DAD method were in a good accordance with the HPLC-DAD and HPLC-FD methods. In addition, the electrophoretic method, as well as the chromatographic methods, was able to separate potential QUI related impurities from the QUI peak. The CITP-CZE-DAD method provided excellent performance parameters that were comparable (precision, accuracy, LOD, robustness) or even better (separation efficiency) than those ones provided by the chromatographic methods. Moreover, the effectivity of the electrophoresis method was higher when considering cost of analysis (equipment, consumption of separation systems), environmental aspects (organicvs. aqueous solvents), on-line sample pretreatment (CITP preconcentration and sample clean-up suitable also for the more complex matrices). Considering these findings, CITP-CZE-DAD was approved as a routine automatized method for the highly reliable quality food control.