Chapter 4: Insight Into Drug Extraction from the Keratin Matrix
Published:18 Dec 2023
Extraction of drugs from the hair matrix is the most critical step in hair analysis. Drugs are bound to keratin, melanin, and other components of hair. During the extraction process they must be released from these unions. The extraction conditions must be carefully selected, since they must be able to extract all the xenobiotics present in the hair and, at the same time, they must not alter the chemical structure or degrade the molecules, especially the most labile ones, such as cocaine or heroin. A variety of extraction methods can be used, and the difference lies in the ability to act on the hair matrix. They range from a simple incubation with apolar solvents, acidic or buffer solutions with different pH to the dissolution of the protein matrix by enzymatic or alkaline digestions. All of these will be reviewed in this chapter and their efficiency to extract different groups of compounds will be compared.