Qualitative screening for basic drugs in autopsy liver samples by dual-plate overpressured layer chromatography

An overpressured layer chromatography (OPLC) method was evaluated for broad-scale screening of basic drugs in 5 g autopsy liver samples using two parallel OPLC systems. Sample preparation included enzymatic digestion with trypsin and liquid-liquid extraction with butyl chloride. Chromatographic separation was performed as dual-plate analysis, with mobile phases composed of trichloroethylene-methylethylketone-n-butanol-acetic acid-water (17:8:25:6:4, v/v) (OPLC1), and butyl acetate-ethanol (96.1%)-tripropylamine-water (85:9.25:5:0.75, v/v). Identification was based on automated comparison of corrected Rf values (hRfc) and in situ UV spectra with library values by dedicated software. The identification limit was determined for 25 basic drugs in liver ranging from 0.5 to 10 mg/kg. The OPLC method proved to be well suited for routine screening analysis of basic drugs in post-mortem samples of varying quality, combining the benefit from moderately high separation power with the ease of disposable plates.