Simultaneous quantitative determination of alpha-ketoglutaric acid and 5-hydroxymethylfurfural in human plasma by gas chromatography-mass spectrometry

alpha-Ketoglutaric acid (alpha-KG) and 5-hydroxymethylfurfural (5-HMF) are currently under investigation as promising cancer cell damaging agents. A method for the simultaneous quantitative determination of alpha-KG and 5-HMF in human plasma was established for screening these compounds in human plasma. Plasma samples were directly treated with O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride to form the corresponding oximes, thus facilitating subsequent liquid-liquid extraction. After formation of the trimethylsilyl ethers, samples were analyzed by gas chromatography with electron ionization mass spectrometry. Stable isotope labeled standards were used, the preparation of C-13(6)-5-HMF is described. Limits of quantitation were set to 0.938 A mu g/mL for alpha-KG and 0.156 A mu g/mL for 5-HMF. Inter-day accuracy was a parts per thousand currency sign93.7% (alpha-KG) and a parts per thousand currency sign92.8% (5-HMF). Inter-day precision was a parts per thousand currency sign6.0% (alpha-KG) and a parts per thousand currency sign4.6% (5-HMF). The method has been successfully applied to pharmacokinetic profiling of the compounds after intravenous application.