甲基黄嘌呤中含量检测方案(液质联用仪)

HITACHIInspire the NextTechnical ReportAS/MSD-004 High Performance Liquid Chromatographyhttp：//www.hitachi-hitec-science.comC2015 Hitachi High-Tech Science Corporation Analysis of Methylxanthines by PDA Detector and Mass Detector Chromaster 5610 MS detector is a new mass detector， designed for LC users， and it isdifferent from conventional mass spectrometers. This time， the analysis examples ofmethylxanthines such as caffeine are introduced here. These components are oftencontained in coffee， cacao products， and supplement drinks. Methylxanthines have acommon basic molecular structure. Therefore， UV spectral patterns are very similar andthe differentiation based only on the UV spectra is difficult. However， a mass detector canprovide the mass information unique to a component， and thus the identificationaccuracy is improved. 5610 MS Detector LC-MS measurement of Methylxanthines series 4 compounds ■ Analytical Conditions Table 2 HPLC Xonsiriona Table 1 MS Detector Setting Conditions lonization method ESI lonization mode Positive lonization voltage 2800V Measurement mode Scan (m/z 100-300) Column LaChrom Ⅱ C18 (3 um)， 4.6 mm I.D. x100 mm Mobile phase A： 0.1%formic acid solution B： 0.1%formic acid solution-Methanol solution B10%(0min)→B50%(5min)→B10%(5.1-8min) Flow rate 1.0mL/min (250：1 sprit) Column Temp. 50°C Detection w.l. DAD 275 nm Injection Volume 10uL ■LC-MS Measurement Each compound， Caffeine， Theobromine， Theophylline and 7-(2-hydroxyethyl)-Theophylline， is dissolvedand diluted with methanol so as to prepare the sample at concentration of 10 p g/mL. Due to the similarchemical structure， UV spectra obtained by DAD have a similarity. However， MS Detector permits to identifythe compounds by the confirmation of [M +H]+ion. 2 3 Detection： DAD 275 nm 2 3 Detection： MSD (Scan) 0 1 2 3 4 5 6 7 8 Time (min) 4.7-(2-Hydroxyethyl)- 1.Theobromine 2. Theophylline 3. Caffeine theophylline Fig. 1 Measurement result of DAD and MS Detector Main system configuration： 5110 Pump， 5210 Autosampler， 5310 Column Oven， 5430 DAD， 5610 MS DetectorNOTE： These data are an example of measurement； the individual values cannot be guaranteed. @Hitachi High-Tech Science Corporation