Hornbeck C L, Barton K M, Czarny R J
Navy Drug Screening Laboratory, San Diego, CA 92134-5298, USA.
J Anal Toxicol. 1995 May-Jun;19(3):133-8. doi: 10.1093/jat/19.3.133.
A new approach to detecting drug positives for cocaine in urine having benzoylecgonine concentrations below the Department of Defense (DoD) cutoffs was examined by measuring the concentrations of the metabolite ecgonine. The DoD cutoff concentrations for determining a positive for cocaine are 150 and 100 ng/mL for radioimmunoassay and gas chromatography-mass spectrometry, respectively. To facilitate this approach, a new assay was developed for ecgonine using only 1 mL urine. The urine was passed through an anion-exchange cartridge, and the eluant was evaporated to dryness in a water bath under nitrogen. The residue was subjected to nonylation and a standard back extraction procedure before a second derivatization with propionic anhydride. A total of 139 urine specimens were analyzed in this manner, and 104 yielded ecgonine concentrations greater than 50 ng/mL. The average ecgonine concentration in the latter specimens was approximately 5 times the comparable benzoylecgonine concentration. By monitoring ecgonine alone or in conjunction with benzoylecgonine, the number of cocaine positives detected in urine could be dramatically increased.
通过测量代谢物芽子碱的浓度，研究了一种检测尿液中苯甲酰芽子碱浓度低于美国国防部（DoD）临界值的可卡因药物阳性的新方法。DoD用于确定可卡因阳性的临界浓度，放射免疫测定法为150 ng/mL，气相色谱 - 质谱法为100 ng/mL。为便于采用这种方法，开发了一种仅使用1 mL尿液检测芽子碱的新检测方法。尿液通过阴离子交换柱，洗脱液在氮气保护下于水浴中蒸发至干。残留物先进行壬酰化和标准反萃取程序，然后用丙酸酐进行第二次衍生化。共以此方式分析了139份尿液标本，其中104份的芽子碱浓度大于50 ng/mL。后一组标本中芽子碱的平均浓度约为可比的苯甲酰芽子碱浓度的5倍。通过单独监测芽子碱或与苯甲酰芽子碱联合监测，尿液中检测到的可卡因阳性数量可显著增加。
