Detection and Quantitation of Xenobiotics in Biological Fluids by ¹H NMR Spectroscopy

Abstract

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 µmol/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.

Keywords :

• Biological fluids
• ¹H NMR spectroscopy
• Poisoning
• Xenobiotics