Determination Of Bromate In Water Research Articles

Electrochemical Sensors for Determination of Bromate in Water and Food Samples-Review.

The application of potassium bromate in the baking industry is used in most parts of the world to avert the human health compromise that characterizes bromates carcinogenic effect. Herein, various methods of its analysis, especially the electrochemical methods of bromate detection, were extensively discussed. Amperometry (AP), cyclic voltammetry (CV), square wave voltammetry (SWV), electrochemiluminescence (ECL), differential pulse voltammetry and electrochemical impedance spectroscopy (EIS) are the techniques that have been deployed for bromate detection in the last two decades, with 50%, 23%, 7.7%, 7.7%, 7.7% and 3.9% application, respectively. Despite the unique electrocatalytic activity of metal phthalocyanine (MP) and carbon quantum dots (CQDs), only few sensors based on MP and CQDs are available compared to the conducting polymers, carbon nanotubes (CNTs), metal (oxide) and graphene-based sensors. This review emboldens the underutilization of CQDs and metal phthalocyanines as sensing materials and briefly discusses the future perspective on MP and CQDs application in bromate detection via EIS.

An innovative platform exploiting solid microcrystalline cellulose for selective separation of bromate species in drinking water: Preparation, characterization, kinetics and thermodynamic study

It is a major challenge to synthesis a cost-effective, efficient and reliable solid phase extractor with exceptional selectivity, capacity and reproducibility for removal of disinfection by-products (DBPs) in drinking water. Thus, the current study extends the analytical utility of microcrystalline cellulose (MCC) as a novel solid extractor against the underexplored bromate ions at trace levels as one of DBPs in drinking water. The proposed MCC platform was prepared via acid (HCl) hydrolysis of cellulose that was isolated from date pits (DPs). Fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopic (TEM) and thermal gravimetric analysis (TGA) were used for characterization of MCC sorbent prepared from DPs (D-MCC). Disappearance of the distinct FTIR peaks of hemicellulose and lignin were observed. The particle size of D-MCC ranged from 2.5 to 4 µm and rougher. SEM micrographs exhibited clear, smooth and stretched polymer structures on the surface and confirmed from the energy dispersive X-ray (EDX) spectra. SEM, TEM images and XRD data also revealed surface agglomeration in microstructures with a satisfactory crystallinity index of 80.81%. High stability of D-MCC was confirmed as compared to raw DPs A dual retention mechanism of bromate involving an ion association interaction of “weak base anion exchanger” and an added component of “surface adsorption” by the available surface area of the D-MCC is proposed. The D-MCC sorbent was successfully used for complete removal of BrO3− ions from environmental water samples. The sorbent presented extraordinary sorption capacity towards bromate ions in comparison to the frequently available extractor counterparts. D MCC can be packed in column for complete separation of trace levels of bromate ions from water from large volumes of water samples without decrease in its performance. Thus, this system can be utilized for ultra-trace determination of bromate in water using the standard addition method. The reusability of MCC towards bromate removal from drinking water is also included.

Automated solid-phase spectrophotometric system for optosensing of bromate in drinking waters

An automated method based on an optosensor included in a multisyringe flow injection system was developed for the determination of bromate in waters for human consumption. The optosensor was based on the formation of a colored radical cation after oxidation of chlorpromazine by bromate and its selective uptake in a mixed-mode cation exchanger sorbent (Discovery DSC-MCAX), placed on a flow-through spectrophotometric cell. In-line regeneration was attained by methanol + 5% (v/v) ammonia, fostering the application of the same sorbent portion up to 180 determinations. Parameters affecting the reaction development and uptake of the colored compound were studied and optimized, while in-line addition of sulfite (≥0.100 g L−1) prevented interference from hypochlorite. The proposed methodology allowed the determination of bromate up to 50.0 μg L−1, with 0.9 μg L−1 as the limit of detection, meeting the requirements of current EU and USA legislation. Application to real drinking water samples was successful, with a mean recovery of 100.2 ± 2.8% for spiked levels of 5.0, 10.0 and 25.0 μg L−1. Repeatability was good (RSD < 3.6%, n = 10) with a determination throughput of 8 h−1, fostering the application to on-line control of water disinfection processes.

Spectrophotometric Determination of Bromate in Water Using Multisyringe Flow Injection Analysis

A multisyringe flow injection system for the spectrophotometric determination of bromate in water is proposed, based on the oxidation of phenothiazine compounds by bromate in acidic medium. Several phenothiazines were tested, including chlorpromazine, trifluoperazine, and thioridazine. Higher sensitivity and lower LOD were attained for chlorpromazine. Interference from nitrite, hypochlorite, and chlorite was eliminated in-line, without any changes in the manifold. The automatic methodology using chlorpromazine allowed the determination of bromate between 25 and 750 µg L−1, with LOD of 6 µg L−1, good precision (RSD < 1.6%, n = 10), and determination frequency of 35 h−1.

Bromate assay in water by inductively coupled plasma mass spectrometry combined with solid-phase extraction cartridges.

Based on selective sorption of bromide, bromoacetic acids (BAA) and bromomethanes on solid-phase extraction (SPE) cartridges, a sensitive and convenient method was developed for the determination of bromate in waters by inductively coupled plasma mass spectrometry (ICP-MS). Dionex OnGuard Ag and reversed-phase (RP) cartridges were tested for retention characteristics for bromide, BAA and bromomethanes. When a sample acidified with nitric acid was passed through an RP cartridge, BAA and bromomethanes were retained, afterwards bromide was absorbed as a precipitate of silver bromide and bromate was unretained when the nearly neutral sample passed a combination of Ag and H cartridges. After SPE pretreatment the recovery of bromate was 96-106%, and bromide remaining in the aqueous phase was found to be less than 0.06 microg L(-1) when the original bromide concentrations were less than 5 mg L(-1). Effectiveness of stacked Ag and H cartridges in removing bromide from chloride-containing samples was also examined. Common cations and other anions did not interfere with bromate determination. The detection limit for bromate is 57 ng L(-1). This method has been applied to analyse waters from various sources, and the recovery of the spiked bromate was in the range of 92-107%.

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.