High performance liquid chromatography with chemiluminescence detection of methamphetamine and its related compounds using 4‐( N , N ‐dimethylaminosulphonyl)‐7‐fluoro‐2,1,3‐benzoxadiazole

A high performance liquid chromatographic assay of methamphetamine (MP) and its related compounds, i.e. ephedrine (EP), norephedrine (NE), p ‐hydroxymethamphetamine ( p ‐HMP), p ‐hydroxyamphetamine ( p ‐HAP) and amphetamine (AP), with peroxyoxalate chemiluminescence detection has been developed. 4‐( N , N ‐Dimethylaminosulphonyl)‐7‐fluoro‐2,1,3‐benzoxadiazole (DBD‐F) was used as a fluorescent labelling reagent. A mixture of hydrogen peroxide and bis[4‐nitro‐2(3,6,9‐trioxadecyloxycarbonyl)phenyl] oxalate in acetonitrile was used as a postcolumn chemiluminogenic reagent. DBD derivatives of MP and its related compounds were separated by a gradient elution with acetonitrile and 0.01 M imidazole buffer (pH 7.0) within 65 min. The detection limits ( S / N = 3) for the proposed method for MP, AP, EP, NE, p ‐HMP and p ‐HAP were 27, 100, 40, 133, 25 and 133 fmol on column, respectively. The recoveries of these compounds with normal urine samples were 87.4–106.4%. The method was successfully applied to the assay of MP and its metabolites in urine samples from MP addicts. A good linear correlation for the resulted amounts of MP or AP between the proposed method and gas chromatography was obtained ( r = 0.993 for MP or 0.991 for AP).