Simultaneous determination of prescription drugs, cocaine, aldicarb and metabolites in larvae from decomposed corpses by LC–MS–MS after solid–liquid extraction with low temperature partitioning

Abstract

The determination of toxic substances in insect larvae collected from corpses in an advanced state of putrefaction can help to elucidate the causa mortis in forensic cases. In this study, an analytical method for the simultaneous determination of six prescription drugs, cocaine and its metabolite benzoylecgonine, and aldicarb and its sulfone and sulfoxide metabolites in larvae was developed and validated. The method involved a solidliquid extraction with low temperature partitioning, and determination by a liquid chromatography-mass spectrometry (LC-MS-MS) method. Significant matrix effects were observed for most analytes, indicating the need to use analytical curves in pre-extracted fortified matrices. The limits of quantification ranged from 1 to 40 ng/g, with precision between 2.83 and 16.9 %. The validated method was used to analyze 28 actual larval samples collected from corpses at the Forensic Medical Institute between 2009 and 2012 in the Federal District, Brazil. At least one substance was present in 11 samples. Benzoylecgonine and diazepam were found in four samples each, followed by cocaine (three samples), carbamazepine (two samples) and amitriptyline (one sample). The method proved to be simple, fast and of low cost, and can be used by forensic laboratories as a complementary tool to elucidate intoxicationrelated deaths where usual toxicological matrices are not available.

Preliminary Analysis of Methamphetamine Detection in Lucilia sericata (Diptera: Calliphoridae) Reared in Methamphetamine-Treated Meat at Various Developmental Stages

“…These and other studies (33,34) point to the significant potential for the study of larvae as a supplemental technique to identify at least most of the chemicals consumed by the deceased, when human remains are uncommon, highly decomposed, or both.…”

Forensic Entomotoxicology: A Brief Look at Sample Preparation Techniques – A Review

“…De Aguiar et al [59] developed and fully validated a SPEsimilar method followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) determination. The sample preparation method was consisted by a solid-liquid extraction with low temperature-partitioning (SLE-LTP) and was applied in larvae matrix collected from decomposed corpses.…”

Highly sensitive mass spectrometric detection of flunitrazepam using magnetic graphene framework enrichment

“…3,4 For this reason, it is very essential to develop a highly sensitive analytical method for monitoring trace levels of unitrazepam in different matrix samples. Until now, several methods have been employed for the determination of benzodiazepines, such as liquid chromatography-mass spectrometry (LC-MS), 5 liquid chromatography-tandem mass spectrometry (LC-MS/MS), [6][7][8][9] high-performance liquid chromatography dual electrode detection, 10 gas chromatography-mass spectrometry (GC-MS), [11][12][13][14] matrix-assisted laser desorption-mass spectrometry (MALDI-MS), 15 desorption electrospray ionization-mass spectrometry (DESI-MS), 16,17 electrochemical methods, 4 spectroscopy, 18,19 and immunoassay. 20 Among these approaches, mass spectrometry (MS) is commonly used for drugs analysis due to its inherent sensitivity, selectivity and capability for providing molecular structure information.…”

“…Liquid-liquid extraction (LLE) and solid phase extraction (SPE) are the most frequently used sample preparation techniques for the enrichment of benzodiazepines. [6][7][8][9]11,12,14 However, LLE suffers from the use of large volumes of toxic organic solvents. SPE requires lengthy multiple-step manual sample processing, it is tedious, timeconsuming, relatively expensive, and sometimes suffers from analyte breakthrough when large sample volumes are analyzed.…”