Schroeder Jennifer L, Marinetti Laureen J, Smith Roy K, Brewer William E, Clelland Brandi L, Morgan Stephen L
Montgomery County Coroner's Office-Miami Valley Regional Crime Laboratory, 361 West Third Street, Dayton, Ohio 45402, USA.
J Anal Toxicol. 2008 Oct;32(8):659-66. doi: 10.1093/jat/32.8.659.
Essential to forensic laboratories is the desire to find a more sensitive, rapid method of analyzing Delta9-tetrahydrocannabinol (THC) and metabolite in biological specimens. Disposable pipette extraction (DPX) is a valuable method in extracting THC and 11-nor-Delta9-tetrahydrocannabinol-9-carboxylic acid (THCc) in blood and THCc in urine. Less waste and solvent usage; smaller specimen volume; clean chromatograms; and utilization of lowcost equipment and consumables were achieved using this method. Differing from traditional solid-phase extraction devices, DPX uses loosely packed sorbent allowing thorough mixing with the specimen without requiring vacuum for elution. Prior to extraction, urine specimens were hydrolyzed and proteins precipitated from blood. Specimen volume requirements were 1 mL of blood and 0.2 mL of urine. The limits of quantitation for THC and THCc in blood were 1 and 2 ng/mL, respectively, and 3 ng/mL for THCc in urine. With R2 values > or = 0.99, blood calibration curves were linear from 1 to 200 ng/mL and 2 to 500 ng/mL for THC and THCc, respectively, with urine THCc linear from 3 to 2000 ng/mL.
法医实验室的关键需求是找到一种更灵敏、快速的方法来分析生物样本中的Δ9-四氢大麻酚（THC）及其代谢物。一次性移液器萃取（DPX）是一种用于从血液中提取THC和11-去甲-Δ9-四氢大麻酚-9-羧酸（THCc）以及从尿液中提取THCc的有价值的方法。使用该方法可减少废物和溶剂用量；降低样本体积；获得干净的色谱图；并能利用低成本的设备和耗材。与传统固相萃取装置不同，DPX使用松散填充的吸附剂，无需真空洗脱即可与样本充分混合。萃取前，尿液样本需进行水解，血液中的蛋白质需沉淀。血液样本体积要求为1 mL，尿液样本体积要求为0.2 mL。血液中THC和THCc的定量限分别为1和2 ng/mL，尿液中THCc的定量限为3 ng/mL。血液校准曲线的R2值≥0.99，THC的线性范围为1至200 ng/mL，THCc的线性范围为2至500 ng/mL，尿液中THCc的线性范围为3至2000 ng/mL。
