Bailey D N
Clin Chem. 1982 Jan;28(1):187-90.
A popular colorimetric analysis for serum acetaminophen, based on ring-nitration of the drug, is demonstrated to yield both "false positives" and erroneously high results for serum from uremic patients. The interference appears to be anionic at physiological pH, and correlates significantly with serum creatine concentration and with the magnitude of the "anion gap." A modification of the analysis involving extraction of the acetaminophen with ether eliminates the interference. As little as 10 mg of drug per liter can be accurately measured in serum by the proposed procedure. Analytical recovery was 97% at a concentration of 1 g/L. Coefficients of variation for the analysis at respective concentrations of 100 and 500 mg/L were: within-run, 2.7% and 2.0%; between-run, 3.1% and 4.2%. I encountered no serious interferences from other drugs. The proposed method, rapid and reliable, is recommended for routine use in the clinical laboratory.
一种基于药物环硝化反应的常用血清对乙酰氨基酚比色分析法，被证明会产生“假阳性”结果，且对尿毒症患者血清的检测结果偏高。这种干扰在生理pH值下似乎是阴离子性的，并且与血清肌酐浓度和“阴离子间隙”大小显著相关。对该分析方法进行改进，采用乙醚萃取对乙酰氨基酚可消除干扰。按照所提出的方法，血清中低至每升10毫克的药物也能被准确测定。在浓度为1克/升时，分析回收率为97%。在100毫克/升和500毫克/升各自浓度下进行分析的变异系数分别为：批内，2.7%和2.0%；批间，3.1%和4.2%。我未遇到来自其他药物的严重干扰。所提出的方法快速且可靠，推荐在临床实验室常规使用。
