Franco de Oliveira Sarah Carobini Werner de Souza Eller, Yonamine Mauricio
Faculty of Pharmaceutical Sciences, University of São Paulo, Brazil.
Faculty of Pharmaceutical Sciences, University of São Paulo, Brazil.
Forensic Sci Int. 2016 Aug;265:81-8. doi: 10.1016/j.forsciint.2016.01.012. Epub 2016 Feb 2.
A gas chromatography-mass spectrometry method for the determination of amphetamines in urine samples by means of liquid-phase microextraction was validated, including calculation of measurement uncertainty. After extraction in the three-phase mode, acceptor phase was withdrawn from the fiber and the residue was derivatized with trifluoroacetic anhydride. The method showed to be very simple, rapid and it required a significantly low amount of organic solvent for extraction. The limits of detection were 10 and 20μg/L for amphetamine and methamphetamine, respectively. The calibration curves were linear over the specified range (20μg/L to 1400μg/L; r(2)>0.99). The method showed to be both precise and accurate and a relative combined uncertainty of 2% was calculated. In order of importance, the factors which were more determinant for the calculation of method uncertainty were: analyte concentration, sample volume, trueness and method precision.
验证了一种通过液相微萃取测定尿液样本中苯丙胺类物质的气相色谱 - 质谱法，包括测量不确定度的计算。在三相模式下萃取后，从纤维中取出接受相，残留物用三氟乙酸酐衍生化。该方法非常简单、快速，且萃取所需的有机溶剂用量极低。苯丙胺和甲基苯丙胺的检测限分别为10μg/L和20μg/L。校准曲线在指定范围内（20μg/L至1400μg/L；r(2)>0.99）呈线性。该方法显示出既精确又准确，计算得出的相对合成不确定度为2%。按重要性排序，对方法不确定度计算更具决定性的因素为：分析物浓度、样本体积、准确性和方法精密度。
