Singh J, Johnson L
Laboratory Services (113), VA Medical Center, Minneapolis, Minnesota 55417, USA.
J Anal Toxicol. 1997 Sep;21(5):384-7. doi: 10.1093/jat/21.5.384.
The Empore disk cartridges (C18) were evaluated for sample preparation in the gas chromatography-mass spectrometry confirmational assay for the 11-nor-9-carboxy-delta 9-tetrahydro-cannabinol (THCCOOH) metabolite. The performance of the Empore disk cartridges, determined by the recovery, precision, limit of detection (LOD), and limit of quantitation (LOQ) of the assay was comparable with the performance of a widely used solid-phase extraction cartridge (Spec C18 cartridges) and the traditional liquid-liquid extraction technique. The Empore disk cartridges showed an average recovery of 89% at low concentrations of 6 ng/mL of the THC metabolite spiked into urine. The recovery was consistent across three different lots of Empore disk cartridges. The within-run precision of the assay at a concentration of 18 ng/mL had a coefficient of variation of 2%, and the LOD and LOQ were determined to be 1 ng/mL.
对Empore盘式柱（C18）进行了评估，用于11-去甲-9-羧基-Δ9-四氢大麻酚（THCCOOH）代谢物的气相色谱-质谱确证分析中的样品制备。通过该分析方法的回收率、精密度、检测限（LOD）和定量限（LOQ）来确定Empore盘式柱的性能，其性能与广泛使用的固相萃取柱（Spec C18柱）以及传统液-液萃取技术的性能相当。对于添加到尿液中的低浓度6 ng/mL的THC代谢物，Empore盘式柱的平均回收率为89%。在Empore盘式柱的三个不同批次中，回收率是一致的。在浓度为18 ng/mL时，该分析方法的批内精密度的变异系数为2%，检测限和定量限分别确定为1 ng/mL。
