The analysis of methadone in nail clippings from patients in a methadone-maintenance program

This study offers an analytical scheme for methadone in fingernail clippings. Nail specimens (0.18-16.33 mg) were collected from 30 consenting adults participating in a methadone-maintenance program along with questionnaires regarding their drug-use histories. The nail clippings were stored in plastic bags and transferred to the laboratory for analysis. They were decontaminated by sonication for 15-min intervals successively in 0.1% sodium dodecyl sulfate, water (three times), and methanol (three times). The methanolic washes were collected and screened for methadone by enzyme immunoassay (EIA). Three washes were found sufficient to provide EIA negative results. The decontaminated nail clippings were hydrolyzed in 1M NaOH. Aliquots of the hydrolysates were screened for methadone by EIA and confirmed by gas chromatography-mass spectrometry (GC-MS). The mean methadone concentrations in fingernail clippings determined by EIA and GC-MS were 32.8 and 26.9 ng/mg, respectively. Hydrolysates of the equivalent of 10 mg of blank nail clippings were spiked with known concentrations of methadone and analyzed by the developed procedures in order to determine extraction recoveries and limits of detection of the two techniques. Based on our results, fingernails appear to be a potentially useful biological specimen for the analysis of methadone and the monitoring of patient compliance to methadone-maintenance programs.