Abstract
Bromate (BrO3-) is a possible human carcinogen which is formed as a bromide containing source water ozone disinfection by-product. Thus, BrO3- is subject to assess its threat to humans. In the present study, an ultra performance liquid chromatography-electrospray ionization mass spectrometry method has been developed for the quantitative analysis of BrO3- in non-alcoholic beer. The chromatographic separation of both transitions (BrO3-)-Br-81 and (BrO3-)-Br-79 (isotope contributions of Br-79 and Br-81) was carried out and achieved in < 1 min, with superior peak symmetry. The good quality parameters were obtained such as linearity (R-2 > 0.9999), precision (repeatability and reproducibility in terms of relative standard deviation) < 1% at 1.0 mg mL(-1) standard and < 3% in the analysis of sample 1 (classic malt) and sensitivity with a low limit of detection (LOD, (BrO3-)-Br-81, 0.03 ng mL(-1) and (BrO3-)-Br-79, 0.03 ng mL-1) and limit of quantification (LOQ, (BrO3-)-Br-81, 0.1 ng mL(-1) and (BrO3-)-Br-79, 0.1 ng mL(-1)) in the standard. Nevertheless, the LOD and LOQ in sample 1 (classic malt) were obtained only for transition (BrO3-)-Br-81, 0.05 ng mL(-1) and 0.16 ng mL(-1), respectively. For transition 79BrO(3)(-) the obtained peak was below the limit of detection. A total of 39 non-alcoholic beer samples of different flavors were analyzed and the 81BrO3- level in classic samples was found between 1.20 mg mL(-1) and 3.73 mu g mL(-1), however, in other flavored samples the concentration levels reached up to 14.04 mg mL(-1) with excellent recovery rates (96-99%). In most of the analyzed real samples, only transition (BrO3-)-Br-81 was found nevertheless, transition (BrO3-)-Br-79 was either < LOD or completely diminished from the obtained sample chromatogram. This is one of the main findings from the present study and the mechanism of this cause is unknown. The obtained BrO3- levels were much higher than the limits in drinking water (10-25 ng mL(-1)) recommended by several regulatory agencies.