Detection of Narcotic Drugs in Urine Samples Using Attenuated Total Reflectance–Fourier Transform Infrared Spectroscopy and Machine Learning Algorithms

Abstract Drug abuse is a substantial problem worldwide, with a prevalence of >2% in Southeast Asia. However, the detection of illegal drugs in urine is time-consuming and requires expert interpretation. Therefore, this study aimed to establish attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy and machine learning algorithms to screen and analyze urine samples of narcotic drug users for methamphetamines and tetrahydrocannabinol. Urine supernatant samples provided clearer absorption peaks compared to the whole urine samples, allowing for better discrimination between nondrug