A novel approach to evaluate the extent and the effect of cross-contribution to the intensity of ions designating the analyte and the internal standard in quantitative GC-MS analysis.
In gas chromatography-mass spectrometry methods of analysis adopting the analyte's isotopic analog as the internal standard (IS), the cross-contribution (CC) phenomenon -- contribution of IS to the intensities of the ions designating the analyte, and vice versa -- has been demonstrated to affect the quantitation data. A novel approach based on the deviations of the empirically observed concentrations of a set of standards was developed to assess the accuracy of the empirically derived CC data. This approach demonstrated that normalization of ion intensities derived from the analyte and the IS generates reliable CC data. It further demonstrated that an ion-pair (designating the analyte and the IS) with approximately 5% or higher CC will result in a very limited linear calibration range.
Chen
Bud-Gen
BG
Department of Medical Technology, Fooyin University, Kaohsiung, Taiwan.
Chang
Chiung Dan
CD
Wang
Chia-Ting
CT
Chen
Yi-Jun
YJ
Chang
Wei-Tun
WT
Wang
Sheng-Meng
SM
Liu
Ray H
RH
D015104:3,4-Methylenedioxyamphetamine / Q000032:analysis; D002138:Calibration; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods* / Q000592:standards*; D004091:Hydromorphone / Q000032:analysis; D007477:Ions / Q000737:chemistry*; D012015:Reference Standards; D015203:Reproducibility of Results
D007477:Ions; D015104:3,4-Methylenedioxyamphetamine; D004091:Hydromorphone