Two simple methods for enantiomeric analyses of urinary amphetamines by GC/MS using deuterium-labeled l-amphetamines as internal standards

Abstract

Two simple methods for enantiomeric analyses of amphetamines in urine by gas chromatography-mass spectrometry (GC-MS) using L-amphetamine-d 3 and L-methamphetamine-d 6 as internal standards are presented. One method (method A) employs extractive derivatization on a diatomaceous column with (S)-(−)-N-(trifluoroacetyl)prolyl chloride (TPC) followed by separation with a conventional capillary column. The second method (method B) uses headspace solid-phase microextraction (HD-SPME) after derivatization with heptafluoro-n-butyryl chloride (HFB), followed by separation with an enantiomeric capillary GC column. By the two methods, all enantiomers were well separated in each chromatogram, and good linearity was obtained in practical concentration ranges (0.1-1.6 µg/ml for method A and 0.05-1 µg/ml for method B) for every compound by selected-ion monitoring. The precision studies indicated satisfactory coefficients of variation (<5%) for every enantiomer at 0.1 µg/ml by both methods. Both methods were also evaluated by applying them to an actual poisoning case. Both methods are recommended for use in forensic analysis, because of their simplicity, high precision, and sufficient sensitivity.

High throughput chiral analysis of urinary amphetamines by GC-MS using a short narrow-bore capillary column

“…Although no data are presented for the recovery rates of ATSs, the rates of their extractive derivatization with TPC were generally satisfactory [14]. Minor losses are compensated by using the deuterated AMP and MAMP as ISs.…”

“…In one of them [14], chiral GC-MS analysis of ATSs was conducted using a regular-size capillary column (30 m long) after derivatization with TPC. In the other report [15], high speed GC-MS analysis of amphetamines was conducted using a short narrow-bore capillary column (5 m long) without chiral separation.…”

“…Three standards (D-AMP, L-AMP, L-MAMP) and deuterated internal standards (ISs; L-AMP-d 3 , L-MAMP-d 6 ) were synthesized in our laboratory [14]. Ethylamphetamine (EAMP), MDA, 4-methylthioamphetamine (4-MTA), MDMA, and 4-bromo-2,5-dimethoxyphenethylamine (2-CB) were gifts from the National Institute of Health Sciences (Tokyo, Japan).…”

Solid-phase microextraction for amphetamines in solid tissues: washing the homogenates with ethyl ether enables their measurements by GC-MS after heptafluorobutyryl derivatization

“…Various methods have been used to analyze amphetamines in body fl uids and hair by SPME-GC-MS with derivatization [3][4][5]7], because derivatization far enhances sensitivity and selectivity. Nowadays, the derivatization of amphetamines in the septum-capped vial using a water-resistant derivatization reagent has become recognized as the best method for automated SPME-GC-MS analysis of amphetamines [4,5,7].…”

“…Nowadays, the derivatization of amphetamines in the septum-capped vial using a water-resistant derivatization reagent has become recognized as the best method for automated SPME-GC-MS analysis of amphetamines [4,5,7]. Our group used HFB-Cl [4,5], while Namera et al [7] used ethyl chloroformate. We compared both reagents and concluded that reactivity of HFB-Cl was higher than that of ethyl chloroformate, and that headspace-SPME can be achieved at lower temperatures for HFB derivatization than for ethyl chloroformate derivatization (unpublished observation).…”