Gas chromatography–mass spectrometry assay for the simultaneous quantification of drugs of abuse in human placenta at 12th week of gestation

We describe the development and validation of a method for the quantification of drugs of abuse, using gas chromatography–mass spectrometry (GC/MS), in human placenta. Concentration ranges covered were 5–500ng/g for amphetamine, methamphetamine, MDMA, methadone, cocaine, benzoylecgonine, cocaethylene, morphine, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol, nicotine, and cotinine. Intra-assay and inter-assay imprecisions were less than 15.7% for lower quality control samples and less than 14.9% for medium and high quality control samples. Recovery range was 36.2–83.7%. Placenta samples were kept at −80°C until analysis; analytes were stable after three freeze–thaw cycles (samples stored at −20°C). This accurate and precise assay has sufficient sensitivity and specificity for the analysis of specimens collected from women who voluntarily terminated their pregnancy at 12th week of gestation. The method has proven to be robust and accurate for the quantification of the principal recreational drugs of abuse in this period of the prenatal life. This is the first report that highlights the presence of drugs of abuse during the first trimester of gestation.