Takayasu T, Ohshima T, Ohtsuji M, Takayama N, Kondo T, Lin Z, Sato Y, Minamino T
Department of Legal Medicine, Kanazawa University Faculty of Medicine, School of Medicine, Japan.
Nihon Hoigaku Zasshi. 1997 Jun;51(3):235-40.
A 17-year-old motorcyclist was killed in a traffic accident. The urine sample collected at autopsy was screened by the Toxi-Lab system; it showed a possible presence of either methamphetamine (MA) or ephedrine (Eph). Gas chromatography-mass spectrometry (GC-MS) was carried out for a trifluoroacetyl (TFA)-derivatized sample after extraction with an Extrelut column. A peak was detected at the same retention time as that of the authentic Eph by GC-MS with a DB-17 wide-bore column; the mass spectrum of the peak was, however, very similar to that of MA. The presence of Eph and absence of MA were proved by GC-MS using a DB-1 column. The Eph in the urine was further confirmed by high performance liquid chromatography (HPLC)-MS using an ODS column. By the REMEDi HS system, Eph and methylephedrine were determined in the urine, and their concentrations (hydrochloride salt) were 0.752 and 2.13 micrograms/ml, respectively. Ethanol was detected as well in the blood (1.55 mg/ml) and urine (2.01 mg/ml) by a pulse heating method. Nicotine, caffeine and dihydrocodeine were also qualitatively detected in the urine by Toxi-Lab, HPLC-MS and REMEDi HS systems. The present case warned that urinary Eph can be misidentified as MA by GC-MS with an intermediately polar column after TFA derivatization.
一名17岁的摩托车手在交通事故中丧生。尸检时采集的尿液样本通过Toxi-Lab系统进行筛查；结果显示可能存在甲基苯丙胺（MA）或麻黄碱（Eph）。用硅藻土柱萃取后，对经三氟乙酰（TFA）衍生化的样本进行气相色谱-质谱联用（GC-MS）分析。使用DB-17宽口径柱的GC-MS在与正品Eph相同的保留时间处检测到一个峰；然而，该峰的质谱与MA的质谱非常相似。使用DB-1柱的GC-MS证实尿液中存在Eph且不存在MA。通过使用ODS柱的高效液相色谱（HPLC）-MS进一步确认尿液中的Eph。通过REMEDi HS系统测定尿液中的Eph和甲基麻黄碱，其浓度（盐酸盐）分别为0.752和2.13微克/毫升。通过脉冲加热法在血液（1.55毫克/毫升）和尿液（2.01毫克/毫升）中也检测到了乙醇。通过Toxi-Lab、HPLC-MS和REMEDi HS系统还对尿液中的尼古丁、咖啡因和二氢可待因进行了定性检测。本案例警示，TFA衍生化后，使用中等极性柱的GC-MS可能会将尿液中的Eph误鉴定为MA。
