Baselt R C, Yoshikawa D, Chang J, Li J
Chemical Toxicology Institute, Foster City, CA.
J Forensic Sci. 1993 Jul;38(4):935-7.
A study was undertaken to determine if a relatively minor modification of our existing specimen collection tubes could enhance the long-term stability of blood cocaine. We added cocaine, benzoylecgonine (BE) and ethanol to whole sheep blood in glass tubes that were prepared to contain one of several combinations of preservatives and anticoagulant. On day 1 and at intervals of up to one year, the drugs were measured by gas chromatography-mass spectrometry (cocaine and BE) or headspace gas chromatography (ethanol). Storage of blood containing 200 ng/mL cocaine at 4 degrees C for one year resulted in 100% loss of the drug using our normal 10 mL specimen collection tubes containing 100 mg sodium fluoride and 20 mg potassium oxalate. The substitution of oxalic acid for potassium oxalate reduced this loss to 76% without any significant effect on the benzoylecgonine or ethanol concentrations. Further addition of 10 mg echothiophate iodide, a quaternary ammonium compound, brought the cocaine loss down to 60% of the original concentration by one year. Further work will be required to determine if oxalic acid and/or echothiophate iodide could be used in blood collection vials intended for forensic toxicological purposes without any detrimental effect on other assays.
开展了一项研究，以确定对我们现有的样本采集管进行相对较小的修改是否能提高血液中可卡因的长期稳定性。我们将可卡因、苯甲酰爱康宁（BE）和乙醇添加到装有几种防腐剂和抗凝剂组合之一的玻璃管中的全羊血中。在第1天以及长达一年的时间间隔内，通过气相色谱 - 质谱法（用于可卡因和BE）或顶空气相色谱法（用于乙醇）对药物进行测量。使用我们正常的含有100 mg氟化钠和20 mg草酸钾的10 mL样本采集管，将含有200 ng/mL可卡因的血液在4℃下储存一年导致药物损失100%。用草酸替代草酸钾可将这种损失降低至76%，而对苯甲酰爱康宁或乙醇浓度没有任何显著影响。进一步添加10 mg碘化依可碘酯（一种季铵化合物），到一年时可卡因损失降至原始浓度的60%。需要进一步开展工作来确定草酸和/或碘化依可碘酯是否可用于法医毒理学目的的血液采集瓶中，而对其他检测没有任何不利影响。
