Detection of meperidine and its metabolites in the hair of meperidine addicts

The presence of meperidine and its metabolites in the hair of meperidine ad dicts was investigated using GC-MS (EI, PCI). Meperidine and its three meta bolites-normeperidine, N-methoxy meperidine and acetyl normeperidine, were found in hair samples from addicted subjects. Methods for the simultaneous determination of meperidine and its metabolites by GC-MS-SIM were also esta blished for human hair samples. After the addition of d(4)-meperidine as an internal standard, hair samples weighing 5 mg were incubated in 0.1 M HCl at 45 degrees C overnight, and the resulting digests were extracted with et her. The recoveries were greater than 80%, with coefficients of variation ( CVs) between 4.48 and 8.31%. The calibration curves for meperidine and norm eperidine in hair were linear over a concentration range of 1 to 500 ng per mg of hair, with correlation coefficients of r=0.9990 and r=0.9992, respec tively. Values less than 0.25 ng/mg of hair were cut off. Hair samples obta ined from 60 drug addicts were analyzed using this method, and the content of meperidine and normeperidine was determined to be 103+/-130 and 117+/-14 3 ng/mg, respectively. Sectional analysis revealed that meperidine was pres ent and stable in hair for at least 20 months, but normeperidine content at the level of the hair root was higher compared to the tip of the hair shaf t. The results also revealed that there was a correlation between the subje ct's drug abuse history and the distribution of drug along the hair shaft, and between the doses of meperidine and drug content presented in hair. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.