Determination of hexamethylenetetramine in foods by high-performance liquid chromatography (HPLC).

A simple and rapid method was developed and validated for the determination of hexamethylenetetramine (HMT) in foods. Samples were homogenised and extracted with methanol, followed by centrifugation. The resulting solution was filtered and injected into the high-performance liquid chromatograph (HPLC). HMT was separated using a Zorbax SCX-300 column coupled to a photodiode array detector. The calibration curve was linear in the range of 1.0-100 μg ml(-1), with good correlation coefficients (r(2) = 0.9992). The recoveries of HMT from foods spiked at levels of 10, 50 and 100 mg kg(-1) ranged from 91.6% to 103.8%, with relative standard deviations (RSDs) between 0.9% and 5.3%. The limit of detection and the limit of quantification of HMT were 0.3 and 1.0 mg kg(-1) based on three food matrixes (provolone cheese, glass noodle and tofu snack), respectively. Uncertainty associated with accuracy contributed mostly to the expanded uncertainty. No detectable levels of HMT were found in any of the samples retailed in Korea. The method was successful in determining HMT in foods.