Detection and quantitation of xenobiotics in biological fluids by 1H NMR spectroscopy

NMR spectroscopic investigation can be applied to a large variety of xenobiotics in acute poisoning cases (therapeutic agents, pesticides, solvents, alcohols). In a salicylate poisoning case, the three major metabolites of acetylsalicylic acid--salicylic, salicyluric, and gentisic acids--have been detected in crude urine. Valproic acid as glucuronoconjugated form was identified in urine samples from two poisoned patients. Paraquat (Gramoxone) was identified by its two aromatic signals at 8.49 and 9.02 ppm and quantitated in urine of two acutely poisoned patients (985 and 500 micromol/L). In an intentional poisoning case with tetrahydrofuran, this compound was characterized by its resonances at 1.90 and 3.76 ppm, and quantitated at 11.3 and 11.8 mmol/L in serum and urine samples, respectively. Methanol, ethylene glycol, and the corresponding metabolites formate and glycolate were detected in the same spectrum of serum samples from three poisoned patients. Detection and quantitation of many exogenous and endogenous compounds could be achieved by 1H HMR spectroscopy in biological fluids without any hypothesis on the chemical species.