GC-MS-MS determination of gamma-hydroxybutyrate in blood and urine.
A gas chromatographic-tandem mass spectrometric (GC-MS-MS) method for determining trace concentrations of gamma-hydroxybutyrate (GHB) in blood and urine has been developed. Multiple reaction monitoring was used to detect parent and daughter ions of GHB, 233 and 147, respectively, following liquid-liquid extraction with acetonitrile and derivatisation with N,O-bis[trimethylsilyl]trifluoroacetamide (BSTFA). Deuterated GHB was used as an internal standard. The assay produced excellent linearity and sensitivity without conversion to gamma butyrolactone. The lower limit of quantitation (LLOQ) in 50 microL of sample was 2.5 microg/mL. The expanded uncertainty values for intra- and interassay results were +/- 0.097 and +/- 0.123 ng/mL at a confidence level of 95% for blood and urine, respectively. Endogenous concentrations of GHB were found to be in the range of 0.3 to 6 microg/mL in urine and 0.5 to 2.3 microg/mL in blood, confirming previously suggested cut-off values for forensic analysis.
Paul
Richard
R
University of Glamorgan, Pontypridd, CF37 1DL, Wales. richpaul@talk21.com
Tsanaclis
Lolita
L
Kingston
Robert
R
Berry
Anthony
A
Guwy
Alan
A
D005554:Forensic Medicine / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D015203:Reproducibility of Results; D012978:Sodium Oxybate / Q000097:blood* / Q000652:urine; D013048:Specimen Handling
D012978:Sodium Oxybate