An improved HPLC analysis of the metabolite furoic acid in the urine of workers occupationally exposed to furfural.

An improved high-performance liquid chromatographic (HPLC) method for the analysis of the metabolite furoic acid in the urine of workers occupationally exposed to furfural is described. The procedure involved an alkaline hydrolysis step followed by solvent extraction using ethyl acetate. HPLC analysis used an acidic acetonitrile/water mobile phase with a C18 column and ultraviolet detection. The overall relative recovery of furoic acid in urine was found to be 98.8% with a relative standard deviation of 9.7%. The limit of quantitation was determined to be 0.01 mmol/L.