Accelerated solvent extraction (ASE) for chromatographic analysis of cocaine and tetrahydrocannabinol analytes in meconium samples

Abstract

Cocaine and cannabis consumption during pregnancy is a relevant public health problem. The number of women users in fertile age is increasing, which leads to a growing concern regarding fetal drug exposure. Adverse outcomes such as low birth weight, intra-uterine growth restriction, preterm birth, neonatal abstinence, neurobehavioral and developmental effects are associated with alcohol, tobacco and illicit drug use during pregnancy. Therefore, is important to obtain data concerning drug misuse during pregnancy to medical and psychological interventions. Self-report drug use by pregnant women is very significant, however often the data are underestimated due to fear of punitive actions. Therefore, confirmation by toxicological analysis of biological matrices must be accomplished. Meconium, the first stool of the newborn, has been proposed as a proper matrix to evaluate fetal exposure since it is collected by and easy and non-invasive way and enables the achievement of long-term information regarding fetal exposure. Although, meconium is a complex matrix, which requires extensive sample cleaning previously to the identification of the analytes. The most common specimen preparation includes methanol homogenization (solid-liquid extraction - SLE) followed by liquid-liquid extraction (LLE) or solid phase extraction (SPE). Those techniques have disadvantages related to the large amounts of organic solvent usage, emulsion formation and multiple steps extraction. The aim of the present research is to develop a method using accelerated solvent extraction (ASE), which allows minor sample handling and also has greater efficiency when compared with conventional techniques, beyond the smaller demand of solvents and more practical application. In association, it will be used the response surface methodology (RSM), a statistical technique that allows to rationalize the optimization of analytical procedures. The identification and quantification of the analytes will be performed by gas chromatography-mass spectrometry (GC-MS). The developed method will be applied in meconium samples from newborns with suspicion of fetal cocaine and cannabinoid exposure, obtained from the University Hospital of São Paulo-USP, Brazil. (AU)