The extraction and infrared identification of gamma-hydroxybutyric acid (GHB) from aqueous solutions.
The chemical analysis of gamma-hydroxybutyric acid (GHB) in most forensic laboratories is complicated by the highly polar nature of the GHB molecule, which makes it unsuitable for direct analysis by gas chromatography (GC). Consequently, a popular analytical approach is to convert GHB into the corresponding lactone or a derivative compound that is then identified by mass spectrometry employed in conjunction with GC (GC/MS). An alternative approach is presented here where GHB may be isolated as a free acid specie from complex aqueous solutions employing a liquid-liquid extraction technique. This approach can yield a relatively pure residue of GHB that presents an infrared transmission spectrum that is sufficiently distinct for identification purposes. Infrared spectroscopy (IR) is a very popular technique that is available to most crime laboratories. The liquid-liquid extraction behavior of GHB is examined in detail and the uniqueness of the infrared spectrum is discussed.
Chappell
John S
JS
Drug Enforcement Administration, Western Laboratory, San Francisco, CA 94105, USA.
Meyn
Ashleigh W
AW
Ngim
Kenley K
KK
D000085:Acetates; D001628:Beverages; D005554:Forensic Medicine / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D006885:Hydroxybutyrates / Q000737:chemistry / Q000302:isolation & purification*; D013287:Illicit Drugs / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D012997:Solvents; D013055:Spectrophotometry, Infrared
D000085:Acetates; D006885:Hydroxybutyrates; D013287:Illicit Drugs; D012997:Solvents; C007650:ethyl acetate