Determination of Antidepressants in Hair via UHPLC-MS/MS as a Complementary Informative Tool for Clinical and Forensic Toxicological Assessments.

Abstract

Hair analysis is a complementary approach for the detection of antidepressants (ADs) in clinical and forensic schemes because it yields a picture of long-term exposure over a time window depending on the length of the hair. A fast and sensitive ultra-high performance liquid chromatography tandem mass spectrometry method using a BEH C18 column with a mobile phase consisting of ammonium acetate/acetonitrile was developed and validated according to international guidelines for the simultaneous analysis of 24 ADs in hair. Methanol/acetonitrile/ammonium formate buffer 1 mmol/L (25:25:50, vol/vol/vol) was used to extract the drugs from the hair matrix before a solid-phase extraction using cation exchange cartridges was applied. Hair samples (n = 18) obtained from a US workplace drug testing center were analyzed to demonstrate the method applicability. The limit of quantification values ranged from 0.006 to 0.05 ng/mg hair, and the calibration curves ranged from the LOQ up to 10 ng/mg hair. The bias and imprecision were <15% for all the compounds except maprotiline (17%). This was evaluated with 2 "in-house" QCs and 1 authentic hair sample from an amitriptyline user. No significant matrix effects for most of the compounds were observed, and the extraction efficiency of the sample cleanup procedure ranged from 40% to 80% (relative standard deviation <15%) [except for demethylcitalopram, didemethylcitalopram, and trazodone (relative standard deviation <33%)]. The method was then successfully applied to the analysis of hair samples from workplace drug testing. The samples were analyzed in 1-cm segments to determine the medication history of the patient. When a sample was reported positive, information concerning the prescription was obtained anonymously for several samples. Concentrations of (minimum-maximum value in ng/mg) citalopram (0.01-132: extrapolated), trazodone (0.01-5.3), sertraline (0.05-0.1), paroxetine (0.02-1.0), bupropion (0.05-0.6), fluoxetine (0.5-8), and amitriptyline (0.2-4.8), including metabolites, are reported. This study may be of interest to clinical and forensic laboratories for interpretation because it demonstrates the AD concentration windows in hair and the link to the prescribed drugs.