Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7615032 | Journal of Chromatography B | 2018 | 30 Pages |
Abstract
Oseltamivir phosphate (OP) is the first line therapy for influenza, and its primary metabolite oseltamivir carboxylate (OC) is the active agent via inhibition of neuraminidase of influenza virus. Dosages of OP and OC might affect human causing nausea and vomiting and it is therefore necessary to evaluate their toxicity and safety. The separation system: liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful technique to monitor OP and OC. However, quantification of OP and OC needs isotopic analogs as internal standards to monitor the stability of the sample pretreatment procedures and instruments. In this study, we demonstrated a modified method (i.e., reductive amination) to synthesize OP and OC deuterated and hydrogenated analogs as internal standards (ISs) and for illustration of calibration curves, respectively. This modification allowed to overcome ISs selection and to enhance the signal intensities via high yield reductive amination in MS detection. We utilized the multiple reaction monitoring (MRM) mode to target m/z values of precursor and product ions. N-dimethylated OP and N-dimethylated OC showed linearity ranging from 1 to 1000â¯ng/mL with coefficient of determination (R2) values of 0.9995 and 0.9999, respectively. Additionally, the relative standard deviations (RSD) of intra-day ranged from 0.3% to 5.2%, and the RSD of inter-day ranged from 2.0% to 18.8%, respectively. This quantitative method utilized spiked OP and OC at low (20â¯ng/mL), intermediate (100â¯ng/mL), and high (500â¯ng/mL) concentrations in human serum samples. The average recoveries for OP and OC were 84.6%-107.7% and 94.9%-98.5%, respectively.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Mei-Fang Huang, Yi-Reng Lin, Yu-Tzu Chang, Yow-Ling Shiue, Shih-Shin Liang,