Valproic acid intoxication identified by 1H and 1H-(13)C correlated NMR spectroscopy of urine samples

Analysis of biological fluids by proton and carbon nuclear magnetic resonance spectroscopy (1H and 13C NMR) is a promising tool in clinical biology. We used this method for rapid toxicological screening in the case of two suicide attempts. For each case, a urine sample was analysed at 300 MHz by 1D and 2D sequences (TOCSY and HMBC) in a short experimental time. Quantification was performed by peak integration on the 1D 1H NMR spectrum. For the two patients, results showed the same resonances of the major metabolite, valproyl-O-glucuronide at concentrations of 121 and 44 mmol/l.