Bromate reduction in simulated gastric juice

Abstract

Bromate decomposition kinetics with simulated stomach/gastric juice was studied to contibute to more accurate determination of the risk of environmentally relevant exposures to bromate. Any presystemic reduction in the stomach would yield lower risks. Bromate is rapidly reduced by hydrogen sulfide (H2S); half‐lives were 153 min at zero H2S and 2, 24, and 32 min at 10−4, 10−5, and 10−6 M H2S, respectively. Half‐lives at 10−4 and 10−5 M are biologically relevant for the retention time for water in an empty stomach. Common dietary inorganic reducing agents (ferrous, iodide, and nitrite) generally enhanced bromate reduction with H2S. Oxidizing agents (hypochlorous acid/chlorine, chloramine, and ferric ion) usually modestly reduced decomposition rates with H2S. Consumption of chlorinated or chloraminated drinking water containing bromate would not materially affect the extent of presystemic bromate reduction. Current studies by the authors are quantifying bromate reduction from the greater systemic liver and blood metabolism, where rapid reactions with glutathione and other reducing agents occur.

Time-dependent integrity during storage of natural surface water samples for the trace analysis of pharmaceutical products, feminizing hormones and pesticides

“…In the case of cyanazine, high instability was detected over the whole duration of storage. This is not a surprise given the recognized sensitivity of cyanazine to hydrolysis in acidic medium which produces a carboxylic acid and another product from the cleavage of the secondary amine [ 22 ]. Cyanazine is also much less stable than atrazine and simazine in surface waters of the USA, and this has been attributed to the oxidation of the cyanazine [ 20 ].…”

What Bathers Put into a Pool: A Critical Review of Body Fluids and a Body Fluid Analog

“…Bromate is known to be reduced by mild reducing agents (ascorbic acid, sulfite, and thiosulfate) in mildly acidic solution (Snyder et al, 2009, p. 26). Cotruvo, Keith, Bull, Pacey, & Gordon (2010) demonstrated BrO 3 -(at 0.2 mg/L) oxidation of I -to I 2 at low pH (pH ∼0.7) even in the absence of other reducing agents. The rate of reaction (expressed as the half-life (t 1/2 ) of BrO 3 -in solution) decreased with increasing I -concentration.…”

What Bathers Put Into a Pool: A Critical Review of Body Fluids and a Body Fluid Analog

“…Bromate is known to be reduced by mild reducing agents (ascorbic acid, sulfite, and thiosulfate) in mildly acidic solution (Snyder et al, 2009, p. 26). Cotruvo, Keith, Bull, Pacey, & Gordon (2010) demonstrated BrO 3 -(at 0.2 mg/L) oxidation of Ito I 2 at low pH (pH ∼0.7) even in the absence of other reducing agents. The rate of reaction (expressed as the half-life (t 1/2 ) of BrO 3in solution) decreased with increasing Iconcentration.…”