Forensic toxicological analysis of hair: a review

Analysis of hair provides useful information regarding drug addiction history or drug toxicity. Keeping in view some important applications of hair analysis, a lot of work done in the past few decades has been reviewed in this article. When compared with other biological samples, hair provides a larger window for drug detection. Drugs get deposited in hair through blood circulation by various mechanisms, after its administration. The deposited drug is much stable and can be detected after a longer period of time as compared with other biological samples, e.g., saliva, blood, and urine. Moreover, segmental analysis can depict multiple or single drug administration by using sensitive analytical techniques. Complex methods for drug extraction and the high cost of analysis are some drawbacks of hair analysis. LC-MS and GC-MS are the prominent among other techniques of choice due to high sensitivity. In this review, detailed knowledge about the drug deposition, extraction, analysis, and application of results in forensic and clinical cases have been discussed.