Roosevelt University1, Biological, Chemical and Physical Sciences, Schaumburg, IL 60173 Georgia Bureau of Investigations - Division of Forensic Sciences2, Chemistry/Drug Identification, Decatur, GA 30037
Analytical Chemistry
USING ATR-IR TO SCREEN FOR GHB IN CLEAN AQUEOUS SOLUTIONS, Tracy L. Pietrucha1, Kristen Leckrone*1, Christian C. Matchett2, Sara H. Roper2, Roosevelt University, Chicago, IL 60605, Department of Biological, Chemical and Physical Sciences1, Georgia Bureau of Investigation, Division of Forensic Sciences, Chemistry Department, P. O. Box 370808, Decatur, Georgia 300372, kleckron@roosevelt.edu
Gamma hydroxybutyrate (GHB) is found naturally in the human body at nanomolar concentrations. Synthetic GHB gained popularity in the US in the 1980’s and 1990’s as a sleep aid, body building supplement and recreational psychoactive. It is also used in drug facilitated sexual assaults (DFSA). The most common form of the drug is the salt form, specifically either sodium or potassium salt. The dosage for the illicit use of GHB is ten milligrams of GHB per kilogram of body mass, or a 1.55 mg/mL solution for a 100 pound person ingesting a 12 oz. drink. This is the dosage that is associated with DFSA; lower dosages are used for illegal recreational effects. The standard analytical technique for positive identification and quantitation of GHB is derivatization followed by gas chromatography/mass spectrometry (GC/MS). However, this is expensive and time consuming and a cheaper, more rapid screening test is desirable. In the experiment, Attenuated Total Reflectance Infrared spectrometry (ATR-IR) was investigated as a possible way to screen for the presence or absence of GHB at or below the illicit dosage. ATR-IR was used in order to accommodate the sample in aqueous solutions. Clean aqueous solutions ranging from the illicit dosage to one-tenth the illicit dosage were analyzed at 25°C. Samples were also analyzed using an ATR-IR heating accessory at 100°C. Finally each solution was evaporated and the residue was resuspended in ethanol prior to ATR-IR analysis. All spectra were compared to a GHB reference spectrum. The temperature controlled ATR-IR and ethanol resuspensions yielded comparable results relative to the reference spectrum, and therefore have potential to serve as a screening tool for aqueous solutions. Future work should investigate the potential interferences from alcoholic drinks and soft drinks, and the potential for liquid-liquid extraction followed by ATR-IR determination as a screening method for GHB in drinks.
[Abstract (DOC)]