GC-MS and HPLC-FLD for sensitive assay of toxic cyclohexylamine in artificial sweetener tablets and human biological fluids.

Abstract

Cyclohexylamine (CHA) is a precursor in the synthesis of artificial sweeteners cyclamate and its major metabolite. CHA is toxic to the nervous system, kidneys, and liver in animal studies. In the present work, gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-fluorescence detection (HPLC-FLD) were introduced for the first time to the determination of nano-level concentration of CHA in artificial sweetener tablets and human biological fluids. According to the obtained results, HPLC-FLD and GC-MS of CHA exhibit a wide linear range from 1 to 1250 ng/mL and 5-1500 ng/mL within limits of detection of 0.49 and 1.55 ng/mL, respectively. Furthermore, both chromatographic techniques exhibited high accuracy and precision, yielding recovery estimates ranging from 95.85 % to 100.70 % for the HPLC-FLD method and 91.54 %-99.64 % for the other while the corresponding values of relative standard deviation (RSD%) range from 0.25 to 0.82 % and 1.25-3.97 %. The accuracies for HPLC-FLD and GC-MS method in serum and urine samples are within the range of 90.29-99.94 %. On the other hand, CHA was detected in all studied artificial sweetener tablets, its level ranged from 1.35 to 102.64 ng/tablet. Also, the results obtained from the HPLC-FLD and GC-MS methods were statistically compared, and no significant difference was found.