Sensitive determination of MDMA and its metabolite MDA in rat blood and brain microdialysates by HPLC with fluorescence detection

A method using high-performance liquid chromatography with fluorescence detection was developed to simultaneously measure MDMA and its metabolite MDA in rat blood and brain microdialysates. The technique, which involves derivatization with DIB-Cl, achieved linear calibration curves for MDA and MDMA over ranges of 2.5–500 and 5.0–1000 ng/mL, respectively. Detection limits were 1.2 ng/mL for MDA and 4.2 ng/mL for MDMA in blood, and 1.3 and 4.8 ng/mL in brain. Precision was under 5.6%. The method was used to monitor MDMA and MDA in rats and to evaluate pharmacokinetic parameters after MDMA administration with or without caffeine.

Study at a glance

Abstract

Abstract Simultaneous determination of 3,4‐methylenedioxymethamphetamine (MDMA) and 3,4‐methylenedioxyamphetamine (MDA) in rat blood and brain microdialysates by high‐performance liquid chromatography with fluorescence detection (HPLC‐FL) was developed. Microdialysates were directly subjected to derivatization with 4‐(4,5‐diphenyl‐1 H ‐imidazol‐2‐yl)benzoyl chloride (DIB‐Cl). The DIB‐derivatives of MDMA, MDA and the internal standard, 1‐methyl‐3‐phenylpropylamine (MPPA), were isocratically separated on an ODS column using a mixture of 50 m m phosphate buffer (pH 7.0)–acetonitrile–methanol–2‐propanol (50:45:5:2, v/v/v/v %) as an eluent at a flow rate of 1.5 mL/min. The calibration curves of MDA and MDMA spiked to blood and brain microdialysates were linear over the ranges 2.5–500 and 5.0–1000 ng/mL, respectively. The detection limits of MDA and MDMA were 1.2 and 4.2 for blood and 1.3 and 4.8 ng/mL for brain, respectively. Additionally, the intra‐ and the inter‐assay precisions were lower than 5.6% for the blood and brain microdialysates ( n = 4). The proposed method was successfully applied for the monitoring of MDMA and its metabolite MDA in rat blood and brain microdialysates, and the pharmacokinetic parameters of MDMA and MDA in the microdialysates after administration of MDMA (5 mg/kg, i.p.) with or without caffeine (20 mg/kg, i.p.) were evaluated. Copyright © 2007 John Wiley & Sons, Ltd.