Gamma-Hydroxybutyric acid (GHB) is a central nervous system (CNS) depressant and hypnotic which, in recent times, has shown an increasingabuse either as recreational drug (due to its euphoric effects and ability to reduce inhibitions) or as doping agent (enhancer of muscle growth).Analogues of GHB, namely gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), share its biological activity and are rapidly converted in vivointo GHB. At present, GHB and analogues are placed in the Schedules of Controlled Substances. Numerous intoxications in GHB abusershave been reported with depressive effects, seizures, coma and possibly death. The purpose of the present work was the development of a rapidanalytical method based on capillary zone electrophoresis for the direct determination of GHB in human urine and serum at potentially toxicconcentrations. Analytical conditions were as follows. Capillary: length 40 cm (to detector), 75um i.d.; buffer: 5.0mM Na2HPO4, 15mMsodium barbital adjusted to pH 12 with 1.0M NaOH; voltage: 25 kV at 23 ◦C; indirect UV detection at 214 nm; injection by application of0.5 psi for 5 s. alfa-Hydroxyisobutyric acid was used as internal standard (IS). Sample pretreatment was limited to 1:8 dilution. Under theseconditions, the sensitivity was ∼3.0 ug/ml (signal-to-noise ratio >3). Calibration curves prepared in water, urine and serum were linearover concentration ranges 25–500 ug/ml with R2 ≥ 0.998. Analytical precision was fairly good with R.S.D. < 0.60% (including intradayand day-to-day tests). Quantitative precision in both intraday and day-to-day experiments was also very satisfactory with R.S.D. ≤ 4.0%.No interferences were found neither from the most common “drugs of abuse” nor from endogenous compounds. In conclusion, capillaryelectrophoresis can offer a rapid, precise and accurate method for GHB determination of biological fluids, which could be important forscreening purposes in clinical and forensic toxicology.
Rapid and direct analysis of gamma-hydroxibutyric acid in urine by capillary electrophoresis-electrospray ionization ion-trap mass spectrometry
GOTTARDO, Rossella;BORTOLOTTI, Federica;TRETTENE, Maristella;DE PAOLI, Giorgia;TAGLIARO, Franco
2004-01-01
Abstract
Gamma-Hydroxybutyric acid (GHB) is a central nervous system (CNS) depressant and hypnotic which, in recent times, has shown an increasingabuse either as recreational drug (due to its euphoric effects and ability to reduce inhibitions) or as doping agent (enhancer of muscle growth).Analogues of GHB, namely gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), share its biological activity and are rapidly converted in vivointo GHB. At present, GHB and analogues are placed in the Schedules of Controlled Substances. Numerous intoxications in GHB abusershave been reported with depressive effects, seizures, coma and possibly death. The purpose of the present work was the development of a rapidanalytical method based on capillary zone electrophoresis for the direct determination of GHB in human urine and serum at potentially toxicconcentrations. Analytical conditions were as follows. Capillary: length 40 cm (to detector), 75um i.d.; buffer: 5.0mM Na2HPO4, 15mMsodium barbital adjusted to pH 12 with 1.0M NaOH; voltage: 25 kV at 23 ◦C; indirect UV detection at 214 nm; injection by application of0.5 psi for 5 s. alfa-Hydroxyisobutyric acid was used as internal standard (IS). Sample pretreatment was limited to 1:8 dilution. Under theseconditions, the sensitivity was ∼3.0 ug/ml (signal-to-noise ratio >3). Calibration curves prepared in water, urine and serum were linearover concentration ranges 25–500 ug/ml with R2 ≥ 0.998. Analytical precision was fairly good with R.S.D. < 0.60% (including intradayand day-to-day tests). Quantitative precision in both intraday and day-to-day experiments was also very satisfactory with R.S.D. ≤ 4.0%.No interferences were found neither from the most common “drugs of abuse” nor from endogenous compounds. In conclusion, capillaryelectrophoresis can offer a rapid, precise and accurate method for GHB determination of biological fluids, which could be important forscreening purposes in clinical and forensic toxicology.
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