Joern W A
J Anal Toxicol. 1987 Mar-Apr;11(2):49-52. doi: 10.1093/jat/11.2.49.
A published gas chromatography/mass spectrometry method for detecting 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH) in urine was modified. In the new procedure, five GC/MS ion peaks of a pentafluoropropylpentafluoropropionyl derivative of THC-COOH are monitored in the multiple-ion mode for improved reliability; two ion peaks of the trideuterated internal standard are used for greater quantitative precision; and methanolic KOH is employed instead of NaOH in the hydrolysis and extraction steps to produce a cleaner extract. Finally, the new procedure is designed to keep THC-COOH either in basic solution or in an organic solvent at all times to prevent adsorption onto glass or plastic, so that disposable, non-silanized glassware may be used. Patient urines were analyzed by both the new procedure and the EMIT method. For 32 specimens, the average and range of EMIT/GC/MS concentration ratios were 2.8 and 0.9-7.2, respectively. Concentrations of THC-COOH measured by the GC/MS procedure may be more indicative of recent marijuana use than the EMIT semi-quantitative concentration values.
一种已发表的用于检测尿液中11-去甲-9-羧基-Δ⁹-四氢大麻酚（THC-COOH）的气相色谱/质谱法被改进。在新方法中，在多离子模式下监测THC-COOH的五氟丙基五氟丙酸酯衍生物的五个气相色谱/质谱离子峰，以提高可靠性；使用氘代内标的两个离子峰以获得更高的定量精度；在水解和萃取步骤中使用甲醇氢氧化钾代替氢氧化钠以产生更纯净的提取物。最后，新方法设计为始终将THC-COOH保持在碱性溶液或有机溶剂中，以防止吸附到玻璃或塑料上，因此可以使用一次性的、未硅烷化的玻璃器皿。通过新方法和EMIT方法对患者尿液进行分析。对于32个样本，EMIT/气相色谱/质谱浓度比的平均值和范围分别为2.8和0.9 - 7.2。与EMIT半定量浓度值相比，通过气相色谱/质谱法测得的THC-COOH浓度可能更能指示近期使用大麻的情况。
