Comments to “Investigations of a new field in gas chromatography” by V.G. Berezkin, A.B. Lapin and J.B. Lipsky

The aim of this study was to evaluate the performance of a technique for simultaneous testing of hydrophilic abuse drugs in hair. The analysis of, codeine and methadone in morphine hair included incubation in methanol (5 h, 50 °C), Surfactant enhanced liquid-phase microextraction (SE-LPME) and HPLC analysis. This study has demonstrated that SE-LPME constitute a real alternative to the other liquid-phase microextraction methods, for pre-concentration and extraction of hydrophilic drugs in biological samples and has shown the advantages of these optimized methodologies over the traditional microextraction techniques. For these drugs recoveries in the range of 57.5–93.7 were obtained from hair. The drugs were enriched by a factor of 61–128 during SE-LPME. Linearity (r2, 0.9982–0.9997) was obtained in the range of 50–500 μg/l for morphine and 10–500 μg/l for codeine and methadone.