Smartphone-based colorimetric determination of gamma-butyrolactone and gamma hydroxybutyrate in alcoholic beverage samples

Honeychurch, Kevin

Abstract

amma-hydroxybutyrate (GBH) is a popular recreational drug. Its strong sedative and amnesic effects have led to drug-facilitated sexual assaults, poisonings, overdose, and death. As a result, legislation has restricted its availability leading to GHB, consumers switching to its pro-drug, gamma-butyrolactone (GBL). Consequently, there is a growing need for methods capable of their determination in complex samples such as beverages. Previous studies have shown the possibility to colorimetrically qualitatively determine both GBH and GBL by the formation of the lactone and its reaction with hydroxylamine and ferric chloride to give a purple-colored complex. In this present investigation, we have shown the possibility of using this approach to both quantify GBL and GHB using both UV/Vis spectrometry and by the application of the camera of a smartphone to record images of the purple color developed. Via subsequent use of a downloadable free App, to extract the numerical values of the Red, Green, and Blue (RGB) color components, it was shown possible to construct a calibration curve and to quantitatively determine the concentration of the drugs present in fortified alcoholic beverage samples. It was found that by simple mathematical normalization of the RGB values the effects of camera distance and elimination could be readily overcome. Using the smartphone approach, GBL determinations on a sample of lager beer gave a mean recovery of 103% (%CV=0.70%, n=5) at a concentration of 0.56 mg/ml indicating the method holds promise for the determination of GBL and GHB in such samples.

Citation

Honeychurch, K. (2023, March). Smartphone-based colorimetric determination of gamma-butyrolactone and gamma hydroxybutyrate in alcoholic beverage samples. Presented at FCN Drugs and Toxicology Meeting, Online (Microsoft Teams)

• Presentation Conference Type: Speech
• Conference Name: FCN Drugs and Toxicology Meeting
• Conference Location: Online (Microsoft Teams)
• Start Date: Mar 20, 2023
• End Date: Mar 20, 2023
• Deposit Date: Mar 21, 2023
• Publicly Available Date: Mar 21, 2023
• Public URL: https://uwe-repository.worktribe.com/output/10572519