ABSTRACT
A method for rapid determination of γ-hydroxybutyric acid (GHB) in beverages (water, sodas, beer) and urine was established by direct analysis real-time mass spectrometry (DART-MS). Samples were analyzed directly after dilution with mixture of methanol and water(1:1,V/V). Instrument parameter settings were optimized to obtain the sensitive and accurate determination of GHB. At the sample introduction speed of 0.5 mm/s, high intensity of[M-H]- ions for GHB were observed in the negative ion and selection ion monitoring mode by utilization of high purity helium gas at 350℃. For different samples of water,sodas,beer and urine,the limits of detection (LODs) (S/N=3) were in the range of 1-2 μg/mL, while the limits of quantification (LOQs) (S/N=10) were in the range of 3-5 μg/mL. The linear correlation coefficients of the standard curves with different sample matrixes were between 0.9899 and 0.9980. The recoveries were in the range of 80.8%-115.2% with the relative standard deviations of 1.9%-12.8%. With its rapid analysis and simple pretreatment steps,the method is expected to have a strong advantage in the rapid screening analysis of large quantities of beverage and urine.