A Study on Photostability of Ethyl Glucuronide in Hair Irradiated Under Artificial Sunlight

The study investigated the photostability of ethyl glucuronide (EtG) in hair exposed to artificial sunlight, which is relevant for forensic toxicologists analyzing drug concentrations. Twenty-eight hair samples previously tested positive for EtG were divided, with one tuft exposed to artificial sunlight and the other kept in the dark. Results showed that 64.3% of the samples exhibited an increase in EtG concentration post-irradiation, ranging from 7% to 255%, while seven samples showed a decrease between -5.0% and -36.0%. The study suggested that changes in EtG concentration could depend on hair color and thickness, and recommended further investigation using a scanning electron microscope to understand the role of hair fiber denaturation and thickness.