Extraction Procedures for Hair Forensic Toxicological Analysis: A Mini-Review

Abstract

In forensic toxicology, drugs of abuse are routinely analyzed due to legal statute in medical or legal investigation, such as death cases, poisoning cases, and drug misuse, determining potential exposure to controlled substances. Despite the widespread use of blood and urine as matrices for forensic toxicological analysis, the use of hair samples has grown as the limitations associated with this matrix are overcome and new areas of application emerge. Hair provides several advantages over urine and blood, such as the easiness of sample collection and the ability to provide a retrospective analysis of drug consumption. Drug analysis in hair is following a path where less amount of sample has been needed to detect drugs of abuse. Improvement in sample preparation methods and lowering detection limits in instrumental analysis is providing forensic scientists with the tools to use drug analysis with hair as a routine approach in the forensic laboratory. Actually, besides the chronological exposition to a drug, hair may provide information about the day a chemical was used. This should become part of the standard information sent by forensic scientists to criminal investigators and courts. The aim of this review is to summon the extraction procedures used to perform forensic toxicological analysis in hair as well as the major advances in this field once a sample preparation step is critical and takes up most of the total analysis time.

Highly stable peptide adducts from hard keratins as biomarkers to verify local sulfur mustard exposure of hair by high-resolution mass spectrometry

“…Accordingly, the formation of adducts with local proteins is expected (Steinritz et al 2021 ). Typical forensic methods make use of hair to detect, e.g., drugs, that either stick to the surface of the hair or have been incorporated into the hair during its growth (Ferreira et al 2019 ). However, these methods do not target agent-induced covalent protein modifications and do not detect adducted peptide biomarkers.…”

Alternative matrices in forensic toxicology: a critical review

“…Melanin has a hydrophobic and acidic nature, which makes this pigment responsible for the affinity of hair to alkaline drugs such as cocaine, codeine and ketamine. Lipophilic and basic molecules are more incorporated than polar analytes [60,62]. Other parameters that can change the concentration of drugs in the hair are the difference of hair growth rate among various anatomic body sites, such as head, pubic, axillary, face and chest hair [63], the washing procedure used before hair analysis and the use of cosmetic and heat hair treatments.…”

“…Accurate and sensitive methods are necessary to detect very low drug concentrations and the cost of analysis is higher than that of other biological samples. Immunoassay tests alone do not provide reliable results and the use of a confirmatory technique such as GC-MS or LC-MS [62] is needed. Interpretation of analytical findings is more complex, considering the complexity and variability of the incorporation of the drugs into hair matrix [71].…”

Hair analysis for New Psychoactive Substances (NPS): Still far from becoming the tool to study NPS spread in the community?

“…Specifically, for NPS more concerns could arise from the absence of specific guidelines for their analysis, the absence of official cut-offs to discriminate consumption from contamination, and from their unknown pharmacology which probably would make necessary the establishment of lower cut-offs in certain cases. Probably, future research could advance the progress of more efficient extraction mixtures or micro extraction methods of diverse NPS from hair [ [77] , [78] , [79] ]. Undoubtedly, an improved universal extraction protocol of NPS from hair will advance the aim of studying the epidemiology of NPS among drug abusers.…”