Using micro-attenuated total reflection spectroscopy to determine chemically induced changes in neat human hair: feasibility study on the effect of antipsychotic drugs

Studying the effect of cocaine on the structure of cosmetically treated human hair using micro-Attenuated Total Reflection spectroscopy (ATR)

It has been demonstrated that hair can accumulate and trap drugs over time with exposure and use, thus being able to provide a useful indication of long-term exposure. Studying changes in the structural components of hair, which may occur as a result of drug binding processes, can be a useful tool in understanding the issues involving false positive results from hair drug testing. Furthermore, the effect of cosmetic treatments, such as bleaching and straightening on hair structural changes, may help to understand the effect of drugs on human hair structure with pre-treatment history. In this investigation, changes resulting from exposure of bleached, unbleached, and straightened, neat blonde Caucasian hair to external cocaine were examined. Cocaine was chosen as the test drug as it is among the most widely abused substances. The results from infrared spectra and their second derivatives with aid of multivariate statistical method, PCA analysis demonstrated that changes in the hair structure occurred as a result of these treatments.

Studying the effect of pH variation on the incorporation of the antipsychotic drug clozapine into dyed and non-dyed hair samples using micro-attenuated total reflection spectroscopy

Antipsychotic drugs are among the mostly widely used medications and are usually taken for prolonged periods of time. Due to its accumulation and trapping of drugs, hair can provide a useful indication of long-term exposure. Of interest also is what if any changes in the structural components of hair occur as a result of the drug binding process. Micro-attenuated total reflection (ATR) spectroscopy is able to examine the structural changes of hair samples by the application of sufficient pressure and without microtoming the hair (A. Koçak and S. L. Berets, Appl. Spectrosc. 62, 803 (2008)). In this investigation, we examined changes resulting from exposure of dyed and undyed hair to external clozapine as a function of the pH of the exposing solution. Single samples from different individuals and in one case from different regions of the scalp from the same individual were analyzed. The results demonstrated that pH related differences exist between drug-exposed dyed and non-dyed samples.