In this work, the interconversion of GHB and GBL in a variety of aqueous media was studied. The effects of solution pH and time were determined by spiking GHB or GBL into pure water and buffered aqueous solutions, and determining the GHB and GBL contents at various time intervals. The degree of GBL hydrolysis to GHB was determined for several commercial aqueousbased GBL products, and further studied as a function of time. The effects of temperature and time were also determined for five commercial beverages spiked with GHB or GBL. GHB and GBL contents were determined using high performance liquid chromatography (HPLC). GHB and/or GBL confirmations were made using gas chromatography-mass spectrometry (GC-MS) and/or infrared spectroscopy (IR). Solution pH, time, and storage temperature were determined to be important factors affecting the rate and extent of GBL hydrolysis to GHB. Under strongly alkaline conditions (pH 12.0), GBL was completely converted to GHB within minutes. In pure water, GBL reacted to form an equilibrium mixture comprising ca. 2:1 GBL:GHB over a period of months. This same equilibrium mixture was established from either GHB or GBL in strongly acidic solution (pH 2.0) within days. A substantial portion of GBL (ca. 1 ⁄ 3) was hydrolyzed to GHB in aqueous-based GBL products, and in spiked commercial beverages, after ambient storage for a period ranging from several weeks to several months. Heat increased and refrigeration decreased the rate of GBL hydrolysis relative to ambient conditions. These studies show that hydrolysis of GBL to GHB does occur in aqueous-based solutions, with samples and time frames that are relevant to forensic testing. Implications for forensic testing and recommendations are discussed.

GHB has been marketed illicitly to bodybuilders and athletes and gamma-hydroxybutyrate (GHB) and gamma-butyrolactone (GBL) to a lesser extent for weight control and as a sleep aid (9). by HPLC/UV-VIS spectrophotometry and HPLC/thermospray Recent reports indicate that GHB use is on the rise and it has mass spectrometry.

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A small amount of green particulate material is encountered in a consumer complaint sample. The green particulates in the sample are identified as a bromethalin-containing rodenticide using high-performance liquid chromatographic (HPLC)-UV-vis spectrophotometric and HPLC-negative-ion atmospheric pressure chemical ionization (APCI)-mass spectrometric (MS) approaches, which are commonly used for the detection and confirmation of bromethalin in grain-based rodenticides. The selective and sensitive nature of the MS detector makes it possible to determine bromethalin without extensive sample cleanup and preconcentration. The estimated detection limit with the UV-vis detector is 500 pg of bromethalin injected into the column. The extensive fragmentation of the bromethalin molecule under APCI conditions provides sufficient structural information for positive identification.

Consumer samples such as food and drugs contaminated with small amounts of green-coloured particles are frequently submitted to the Forensic Chemistry Center for analysis. Based on the green colour of the contaminant, and the history of the sample, it has been suggested that the particles may be present due to commercially available rodenticides. As the commonly used active ingredient of such rodenticides is the superwarfarin brodifacoum { 34344'bromobiphenyl-4-yl)-1,2,3,4-tetrahydro-l-naphthyl]-4-hydroxycoumarin} , a simple method for the determination of brodifacoum in wheat-based commercial rodenticides in samples as small as 2 mg has been developed. A small amount of the green particulate material is sonicated in a methanol-methanoic acid mixture for 15 min and analysed by reversed-phase HPLC with a fluorescence detector. The selective and sensitive nature of the fluorescence detector makes it possible to determine brodifacoum without extensive sample clean-up and preconcentration. The estimated detection limit is 4 pg of brodifacoum injected into the column and recoveries are 86 and 99% for two popular commercial brands.