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PubMed2000

Comparison of ion chromatographic methods based on conductivity detection, post-column-reaction and on-line-coupling IC-ICP-MS for the determination of bromate.

An established method for the determination of the disinfection by-product bromate is ion chromatography (IC). This paper presents a comparison of three IC methods based on either conductivity detection (IC-CD), a post-column-reaction (IC-PCR-VIS) or the on-line-coupling with inductively coupled plasma mass spectrometry (IC-ICP-MS). Main characteristics of the methods such as method detection limits (MDL), time of analysis and sample pretreatment are compared and applicability for routine analysis is critically discussed. The most sensitive and rugged method is IC-ICP-MS, followed by IC-PCR-VIS. The photometric detection is subject to a minor interference in real world samples, presumably caused by carbonate. The lowest sensitivity is shown by the IC-CD method as slowest method compared, which, in addition, requires a sample pretreatment. The highest amount of information is delivered by IC-PCR-VIS, which allows the simultaneous determination of the seven standard anions and bromate.

Anions↗
PubMed1989

Effect of route of administration in the micronucleus test with potassium bromate.

The effect of intraperitoneal injection (i.p.) versus oral gavage administration (p.o.) of potassium bromate was examined using the micronucleus test in 2 strains of male mice (MS/Ae and CD-1). First, a small acute toxicity test and a pilot micronucleus experiment were performed to determine the appropriate dose range and sampling time for the full-scale micronucleus test. The full-scale test was carried out using doses of 18.8, 37.5, 75, and 150 mg/kg in the i.p. test and of 37.5, 75, 150, and 300 mg/kg in the p.o. test. The sampling time was 24 h for both mouse strains. Potassium bromate induced micronucleated polychromatic erythrocytes (MNPCEs) dose-dependently by both routes of administration in both mouse strains. No distinct difference in route of administration was observed in the test with MS/Ae mice. In CD-1 mice more MNPCEs were induced by the i.p. route than by the p.o. route.

Administration, Oral↗
PubMed2005

Adsorption of fluoride, chloride, bromide, and bromate ions on a novel ion exchanger.

A novel ion exchanger based on double hydrous oxide (Fe2O3Al2O3xH2O) was obtained by the original sol-gel method from easily available and cheap raw materials and employed for adsorption of F-, Cl-, Br-, and BrO-3 from simultaneous solutions. Adsorbent was characterized by potentiometric titration, zeta-potential, and poremetrical characteristics. A technologically attractive pH effect of F-, Br-, and BrO-3 sorption on the investigated double hydroxide of Fe and Al, which is capable of working in the pH range 3 to 8.5, was observed. Kinetic data on fluoride and bromide sorption fit well the pseudo-second-order model. Isotherms of fluoride, bromide, chlorine, and bromate ion sorption on Fe2O3Al2O3xH2O were obtained at pH 4. The isotherm of F- sorption fit well the Langmuir model; sorption affinity (K=0.52 L/mg) and sorption capacity (90 mg F/g) were high. In the competitive adsorption of bromide and bromate, bromide dominated at equilibrium concentrations of the ions >40 mg/L. The mechanism of fluoride adsorption to the surface of the model cluster of the sorbent synthesized and the geometry of the cluster itself were modeled with the HyperChem7 program using the PM3 method.

Adsorption↗
PubMed2006

Mechanism of DNA damage induced by bromate differs from general types of oxidative stress.

A representative reactive oxygen species (ROS), hydroxyl radical (*OH), is a highly reactive species and induces DNA backbone breakage. *OH also oxidizes every DNA base. The interaction of *OH with guanine leads to the generation of not only piperidine-resistant 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) but also various piperidine-labile products. On the other hand, potassium bromate (KBrO3) induces specific formation of 8-oxodG in the presence of SH compounds, such as glutathione (GSH) and cysteine (Cys). GSH/Cys reduces KBrO3 (BrO3-) to BrO2, which abstracts one electron from guanine. The one-electron oxidation of guanine may yield cation radicals followed by the reaction with a water molecule, leading to 8-oxodG formation. Therefore, mechanism of bromate-induced oxidative DNA damage is different from general types of oxidative stress such as *OH.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2005

Ozone decomposition of 2-methylisoborneol (MIB) in adsorption phase on high silica zeolites with preventing bromate formation.

This work elucidates the applicability of our newly developed adsorptive ozonation process for the decomposition of 2-methylisoborneol (MIB), a typical taste and odor chemical, without the formation of possibly carcinogenic bromate ions. First, zeolite adsorbents were screened for their ability to adsorb MIB with a batch-type adsorption experimental apparatus and a flow-type decomposition experimental apparatus included an adsorbent-packed column. The USY zeolite with the highest silica to alumina ratio (SiO(2)/Al(2)O(3) molar ratio=70) showed the best performance as an adsorbent. Using this adsorbent, an ozonation experiment on an MIB solution including bromide ions was performed under various retention times using the flow-type apparatus. As a result, sufficient decomposition of MIB was achieved with preventing bromate formation.

Adsorption↗
PubMed1998

Determination of trace level bromate in drinking water by direct injection ion chromatography.

Disinfection byproduct anions such as bromate, chlorite and chlorate pose significant health risks, even at low microgram/l levels in drinking water. A direct injection, ion chromatographic method was developed using a Dionex AS9-HC anion-exchange column with a carbonate eluent and suppressed conductivity detection for the determination of these disinfection byproduct anions, and bromide, at low microgram/l levels in drinking water. No additional sample pretreatment, other than filtration, is required. The method is linear for the oxyhalides and bromide over the typical concentration range expected for these analytes in drinking water; and quantitative recoveries were obtained for drinking water samples spiked at 10 micrograms/l. This ion chromatographic method, based on the recently developed AS9-HC column, is applicable for the quantitation of bromate in finished drinking water at the 10 micrograms/l maximum contaminant level currently being proposed by the US EPA.

Bromates↗
PubMed1990

Bromate intoxication: hairdressers' anuria.

A 17-year-old hairdresser developed sodium bromate poisoning after drinking a cup of hair neutralizer in a suicide attempt. She presented 1 week later with anuria, required hemodialysis for 5 days, and subsequently recovered. Sensorineural hearing loss, often a characteristic finding, was absent. Early diagnosis of bromate intoxication requires an appreciation that it commonly occurs in hairdressers, may be accompanied by deafness, and may present with insidious anuria.

Adolescent↗
PubMed2002

Kinetic-spectrophotometric determination of ascorbic acid by inhibition of the hydrochloric acid-bromate reaction.

A new analytical method was developed for the determination of ascorbic acid in fruit juice and pharmaceuticals. The method is based on its inhibition effect on the reaction between hydrochloric acid and bromate. The decolourisation of Methyl Orange by the reaction products was used to monitor the reaction spectrophotometrically at 510 nm. The linearity range of the calibration graph depends on bromate concentration. The variable affecting the rate of the reaction was investigated. The method is simple, rapid, relatively sensitive and precise. The limit of detection is 7.6 x 10(-6) M and calibration rang is 8 x 10(-6)-1.2 x 10(-3) M ascorbic acid. The relative standard deviation of seven replication determinations of 8 x 10(-6) and 2 x 10(-5) M ascorbic acid was 2.8 and 1.7%, respectively. The influence of potential interfering substance was studied. The method was successfully applied for the determination of ascorbic acid in pharmaceuticals.

Ascorbic Acid↗
PubMed2003

Spectrophotometric reaction rate method for determination of barbituric acid by inhibition of the hydrochloric acid-bromate reaction.

A new kinetic-spectrophotometric method was developed for the determination of barbituric acid. The method is based on its inhibition effect on the reaction between hydrochloric acid and bromate. The decolorization of methyl orange by the reaction products was used to monitor the reaction spectrophotometrically at 510 nm. The variable affecting the rate of the reaction was investigated. The method is simple, rapid, relatively sensitive and precise. The limit of detection is 7.9x10(-7) M and calibration rang is 1x10(-6)-6.0x10(-4) M barbituric acid. The linearity range of the calibration graph is depends on bromate concentration. The relative standard deviation of seven replication determination of 5.6x10(-6) M barbituric acid was 1.8%. The influence of potential interfering substance was studied.

Barbiturates↗
PubMed2001

MTBE oxidation by conventional ozonation and the combination ozone/hydrogen peroxide: efficiency of the processes and bromate formation.

The present study investigates the oxidation of methyl tert-butyl ether (MTBE) by conventional ozonation and the advanced oxidation process (AOP) ozone/hydrogen peroxide under drinking water treatment conditions. The major degradation products identified were tert-butyl formate (TBF), tert-butyl alcohol (TBA), 2-methoxy-2-methyl propionaldehyde (MMP), acetone (AC), methyl acetate (MA), hydroxyisobutyraldehyde (HiBA), and formaldehyde (FA). The rate constants of the reaction of ozone and OH radicals with MTBE were found to be 0.14 and 1.9 x 10(9) M(-1) s(-1), respectively. The rate constants for the same oxidation processes were also measured for the degradation products TBF, MMP, MA, and HiBA (k(O3-TBF) = 0.78 M(-1) s(-1); k(OH-TBF) = 7.0 x 10(8) M(-1) s(-1); k(O3-MMP) = 5 M(-1) s(-1); k(OH-MMP) = 3 x 10(9) M(-1) s(-1), k(O3-MA) = 0.09 M(-1) s(-1), k(O3-HiBA) = 5 M(-1) s(-1); k(OH-HiBA) = 3 x 10(9) M(-1) s(-1)). Since all compounds reacted slowly with molecular ozone, only the degradation pathway of MTBE with OH radicals has been determined, including the formation of primary degradation products. In experiments performed with several natural waters, the efficiency of MTBE elimination and the formation of bromate as disinfection byproduct have been measured. With a bromide level of 50 microg/L, only 35-50% of MTBE could be eliminated by the AOP O3/H2O2 without exceeding the current drinking water standard of bromate (10 microg/L). The transient concentrations of MTBE and its primary degradation products were modeled using a combination of kinetic parameters (degradation product distribution and rate constants) together with the ozone and OH radical concentration and were in good agreement with the experimental results.

Ammonia↗
PubMed2003

Characterization of sulfur speciation in low molecular weight subunits of glutenin after reoxidation with potassium iodate and potassium bromate at different pH values using x-ray absorption near-edge structure (XANES) spectroscopy.

Sulfur speciation in low molecular weight (LMW) subunits of glutenin after reoxidation with potassium iodate and potassium bromate at different pH values, aged subunits of glutenin as well as gluten, and gliadin have been investigated in situ by S K-edge X-ray absorption near-edge structure (XANES) spectroscopy. XANES spectra were analyzed quantitatively using a least-squares fitting routine to provide relative percentage contribution of different sulfur species occurring in the samples. Using potassium iodate and potassium bromate for reoxidation of reduced LMW subunits of glutenin led not only to disulfide states but also to higher oxidation states (sulfoxide state, sulfonic acid state). Strongest oxidation occurred at low pH values. Higher oxidation states were also predominantly detected in the aged subunits of glutenin, whereas the disulfide state was the main sulfur species in gluten and gliadin samples. The results showed that the oxidation state of sulfur prior to oxidation (thiol, disulfide) strongly influences sulfur speciation after oxidation. The choice of the oxidizing reagent seems to be of minor importance.

Bromates↗
PubMed2000

Influence of reagent purity on the ion chromatographic determination of bromate in water using 3,3'-dimethoxybenzidine as a prochromophore for photometric detection.

Variable availability of the purified dihydrochloride salt of 3,3'-dimethoxybenzidine (DMB; ortho-dianisidine) led us to investigate the effects of reagent purity on the analytical results obtained when this reagent is used in the photometric determination of the disinfection byproduct bromate. After analyte ions are separated by ion chromatography, a solution of DMB (post-column reagent) is added to the eluate and the DMB is oxidized, thereby producing a chromophore detected by its absorbance. Although some commercial products of undefined grade performed well, others did not. Variability was also observed between lots of purified material. Sensitivity at low concentrations (< 5 micrograms L-1 BrO3-) varied by a factor of up to 10. In some cases, the lower limit of detection for photometric detection was greater than that obtained using conductivity detection, as high as 5-7 micrograms L-1 BrO3-. An impurity or several impurities are suspected to be responsible for deviations from linearity at low analyte concentrations. This investigation underscores the need for ensuring reagent purity in environmental analyses. Ideally, chemical manufacturers will meet the needs of analytical chemists who test potable water and begin producing a high grade material in sufficient quantities to meet monitoring requirements. The establishment of third-party standards for a spectrophotometric grade of DMB.2HCl would be helpful in ensuring that a variety of manufacturers could supply products of uniformly high quality that would be suitable for the measurement of bromate in public drinking water supplies.

Bromates↗
PubMed2000

Br concentration as an indication of pre-baking bromation of bread products.

Br concentration in bread for baked bread products was shown to be linearly proportional to the amount of Br added per kg of flour used to make the product. Br concentration in bread can be used to help identify those bread products with the greatest likelihood of containing bromate residues. Instrumental neutron activation analysis was used to determine Br in test portions of bread products from commercial bakeries, homemade bread, flour, and unbaked dough. High performance liquid chromatography was used to determine the bromate residue in selected test portions.

Bread↗
PubMed1981

Toxicity of bromate to striped bass ichthyoplankton (Morone saxatilis) and juvenile spot (Leiostomus xanthurus).

Striped bass (Morone saxatillis) eggs (12 h after fertilization) and larvae (4 d after hatching) and juvenile spot (Leiostomus xanthurus) were exposed to a series of bromate concentrations for 4, 10, and 10 d, respectively, using static replacement bioassay techniques. Three-dimensional mortality response surfaces were constructed by computerized probit regression techniques. Newly hatched striped bass prolarvae were most sensitive to bromate and had a 96-h LC50 of 30.8 mg/l (as BrO3-). Four-day-old striped bass larvae were less sensitive, with 2- to 10-d LC50s ranging from 605.0 to 92.6 mg/l BrO3-, respectively. Juvenile spot were least sensitive, with 1- to 10-d LC50s ranging from 698.0 to 278.6 mg/l BrO3-, respectively.

Animals↗
PubMed2001

Immunotoxicity of sodium bromate in female B6C3F1 mice: a 28-day drinking water study.

Bromate is one of the water disinfection by-products (DBPs) produced during the process of ozonation. The purpose of this study was to evaluate the immunotoxic potential of sodium bromate (SB) in female B6C3F1 mice. SB was administered in the drinking water for 28 days at doses of 80-800 mg/l. There was no difference in drinking water consumption between the animals exposed to SB and the tap water controls. Exposure to SB did not produce any signs of overt toxicity. Furthermore, no significant differences were observed in body weight, body weight gain, or the weights of thymus, liver, kidneys or lungs. No gross pathological lesions were observed in SB-treated animals. However, animals exposed to SB had a significant increase in absolute (28%) and relative (26%) spleen weights. The erythrocyte count, hemoglobin, hematocrit, mean corpuscular volume (MCV), platelet count, total leukocyte count, and counts of differential leukocytes were unaffected by SB. A dose-related increase in reticulocytes was observed following exposure to SB with the greatest increase (78%) observed at the highest dose level. Overall, there were no changes in the absolute number of total T cells, CD4+CD8- T cells, CD4-CD8+ T cells, natural killer (NK) cells and macrophages. Exposure to SB did not affect the percentage of B cells, although a slight increase in absolute number of B cells at the dose of 600 mg/l was observed. There was no alteration in IgM antibody-forming cell (AFC) response, mixed leukocyte reaction (MLR) and NK cell activity after exposure to SB. When the activity of peritoneal macrophages, unstimulated or stimulated with IFN-gamma and LPS, was evaluated using the cytotoxic/cytostatic assay of B16F10 tumor cells, the suppressive effect of macrophages on the proliferation of B16F10 tumor cells was decreased after exposure to SB. In conclusion, SB, when administered in the drinking water at doses from 80 mg/l to 800 mg/l, produced minimal toxicological and immunotoxic effects in female B6C3F1 mice.

Animals↗
PubMed1992

Two children with bromate intoxication due to ingestion of the second preparation for permanent hair waving.

We report two children who suffered from sodium bromate intoxication due to ingestion of the second preparation for permanent hair waving (the second permanent preparation). One child suffered from gastrointestinal symptoms only. The other exhibited slight acute renal insufficiency. Results of the histological examination of the kidney in the sick child with acute renal insufficiency showed sporadic epithelial separation of the proximal tubuli under light microscopy. In addition, we could demonstrate more clearly epithelial separation and unbroken tubular basement membranes under electron microscopy (EM). To our knowledge, this is the first report of EM findings in this disease. The mechanism of epithelial injuries by bromate is not clear.

Acute Kidney Injury↗
PubMedDate not supplied

Carcinogenicity of potassium bromate administered in the drinking water to male B6C3F1 mice and F344/N rats.

Ozone has been proposed for water disinfection because it is more efficient than chlorine for killing microbes and results in much lower levels of carcinogenic trihalomethanes than does chlorination. Ozone leads to formation of hypobromous acid in surface waters with high bromine content and forms brominated organic by-products and bromate. The carcinogenicity and chronic toxicity of potassium bromate (KBrO3) was studied in male B6C3F1 mice and F344/N rats to confirm and extend the results of previous work. Mice were treated with 0, 0.08, 0.4, or 0.8 g/L KBrO3 in the drinking water for up to 100 wk, and rats were provided with 0, 0.02, 0.1, 0.2, or 0.4 g/L KBrO3. Animals were euthanatized, necropsied, and subjected to a complete macroscopic examination. Selected tissues and gross lesions were processed by routine methods for light microscopic examination. The present study showed that KBrO3 is carcinogenic in the rat kidney, thyroid, and mesothelium and is a renal carcinogen in the male mouse, KBrO3 was carcinogenic in rodents at water concentrations as low as 0.02 g/L (20 ppm; 1.5 mg/kg/day). These data can be used to estimate the human health risk that would be associated with changing from chlorination to ozonation for disinfection of drinking water.

Animals↗
PubMedDate not supplied

Time- and dose-dependent development of potassium bromate-induced tumors in male Fischer 344 rats.

Potassium bromate (KBrO3) is a rodent carcinogen and a nephro- and neurotoxicant in humans. KBrO3 is used in cosmetics and food products and is a by-product of water disinfection by ozonization. KBrO3 is carcinogenic in the rat kidney, thyroid, and mesothelium and is a renal carcinogen in the male mouse. The present study was designed to investigate the relationship of time and dose to bromate-induced tumors in male Fischer 344 (F344) rats and to provide some insight into the development of these tumors. KBrO3 was dissolved in drinking water at nominal concentrations of 0, 0.02, 0.1, 0.2, and 0.4 g/L and administered to male F344 rats as the sole water source for 12, 26, 52, 78, or 100 wk. Renal cell tumors were present after 52 wk of treatment only in the high-dose group. Mesotheliomas developed after 52 wk of treatment on the tunica vaginalis. Mesotheliomas were present at sites other than the testicle after 78 wk of treatment, indicating that their origin was the testicular tunic. Thyroid follicular tumors were present as early as 26 wk in 1 rat each from the 0.1- and 0.2-g/L groups. The present study can be used as a basis for the determination of dose-time relationships of tumor development for a better understanding of KBrO3-induced cancer.

Adenoma↗