Analysis of zopiclone (Imovane) in postmortem specimens by GC-MS and HPLC with diode-array detection

A 26-year-old black female was found dead at home. Her mouth was covered with a fluid containing chalky particles. Empty strips of Imovane (zopiclone) and an empty bottle of Fortal (pentazocine) were also found. No urine was available at autopsy. Screening of postmortem blood and stomach contents with enzyme-multiplied immunoassay technique (EMIT) detected only caffeine. Further screening using routine high-performance liquid chromatography (HPLC) with diode-array detection and gas chromatography (GC) with mass spectrometric detection revealed the presence of large amounts of pentazocine in the blood and stomach contents. In the HPLC chromatogram, a second peak that was only partially resolved from the solvent front was observed. Thin-layer chromatography demonstrated the presence of zopiclone, but optimized HPLC and GC conditions had to be used for proper identification and quantitation. This case illustrates the fact that zopiclone can be easily overlooked during routine forensic screening.