소변 시료 중 메스암페타민 및 암페타민 광학이성질체 농도 측정 결과의 불확도 평가

Uncertainty Evaluation for Determination of Methamphetamine and Amphetamine Enantiomers in Urine

The objective of this study was to assess the measurement uncertainty for determination of methamphetamine and amphetamine enantiomers in urine sample by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The deuterium-labeled compounds were prepared for use as internal standards to quantify the analytes. Urine sample (200 μl) was diluted with pure water before the solid phase extraction (SPE). The sample was extracted and purified using Oasis HLB SPE cartridge followed by chromatographic separation on a vancomycin-based chiral column (150 mm×2.1 mm, 5 μm). The mass spectrometric analysis were performed in multiple reactions monitoring (MRM) selecting three precursor/ fragment ion pairs for each analyte. The potential sources that contribute uncertainty to the final result were evaluated. The major contributing factors impacting the combined standard uncertainty were calibration curve and repeatability, while the preparation of standard solution and sample dilution were minor factors. Relative expanded uncertainty of the measured analyte concentration was within 8.5% in a forensic urine sample.