Decrease In Absorbance Research Articles

A versatile platform for colorimetric, fluorescence and photothermal multi-mode glyphosate sensing by carbon dots anchoring ferrocene metal-organic framework nanosheet.

Concerns regarding pesticide residues have driven attempts to exploit accurate, prompt and straightforward approaches for food safety pre-warning. Herein, a nanozyme-mediated versatile platform with multiplex signal response (colorimetric, fluorescence and temperature) was proposed for visual, sensitive and portable detection of glyphosate (GLP). The platform was constructed based on a N-CDs/FMOF-Zr nanosensor that prepared by in situ anchoring nitrogen-doped carbon dots onto zirconium-based ferrocene metal-organic framework nanosheets. The N-CDs/FMOF-Zr possessed excellent peroxidase (POD)-like activity and thus could oxide colorless 3, 3', 5, 5'-tetramethylbenzidine (TMB) into a blue oxidized TMB (oxTMB) in presence of H2O2. Intriguingly, owing to the blocking effect triggered by multiple interaction between GLP and N-CDs/FMOF-Zr, its POD-like activity of the latter was remarkably suppressed, which can modulate the transformation of TMB into oxTMB, generating tri-signal responses of fluorescence enhancement, absorbance and temperature decrease. More significantly, the temperature mode can be facilely realized by a portable home-made mini-photothermal device and handheld thermometers. The proposed multimodal sensing was capable of providing sensitive results by fluorescence mode and simultaneously realized visual/portable testing by colorimetric and photothermal channels. Consequently, it exhibited more adaptability for practical applications, which can satisfy different testing requirements according to sensitivity and available instruments/meters, presenting a new horizon for exploiting multifunctional sensors.

Experimental Study on the Manufacturing of Functional Paper with Modified by N-Methylmorpholine-N-oxide Surfaces.

The manufacturing of paper with new functional properties is a current problem today. A method of modifying the surface layer of paper by the partial dissolution of cellulose on its surface is proposed. N-Methylmorpholine-N-oxide (NMMO) is proposed for use as a solvent, the regeneration of which provides an environmentally friendly process. It was shown that among the possible hydrate forms of the solvent, the monohydrate and higher-melting forms are optimal for modifying the paper surface. The temperature-time modes of processing were revealed and the weight gain and density increase in the course of modification were estimated. The structural and morphological features of the original and modified paper were studied by X-ray imaging and scanning microscopy. The NMMO surface treatment makes it possible to vary the air permeability of the paper, making it practically non-permeable. The capillary and pore system were radically transformed after the partial dissolution of cellulose and its coagulation, as the formed cellulose film isolates them, which leads to a decrease in surface absorbency. The processing conditions allowing for the optimization of the optical and strength properties of the modified paper samples are revealed. The resulting paper with a modified N-methylmorpholine-N-oxide surface layer can be used for printing valuable documents.

Colorimetric Determination of Adenylation Domain Activity in Nonribosomal Peptide Synthetases by Using Chrome Azurol S.

Adenylation domains are the main contributor to structural complexity among nonribosomal peptides due to their varied but stringent substrate selection. Several in vitro assays to determine the substrate specificity of these dedicated biocatalysts have been implemented, but high sensitivity is often accompanied by the cost of laborious procedures, expensive reagents or the requirement for auxiliary enzymes. Here, we describe a simple protocol that is based on the removal of ferric iron from a preformed chromogenic complex between ferric iron and Chrome Azurol S. Adenylation activity can be rapidly followed by a decrease in absorbance at 630 nm, visualized by a prominent color change from blue to orange.

Revealing surface modifications of caesium indium selenium treated Cu-rich Cu(In,Ga)Se2: A study of the suppression of the interfacial recombination

Cu(In,Ga)Se2 (CIGS) solar cell is a kind of high efficiency thin film photovoltaic device. These CIGS solar cells with high efficiency tend to be Cu-poor. Actually, the Cu-rich CIGS solar cells which have the superior electrical characteristics should have higher efficiency compared with the Cu-poor ones. However, the performance (especially the VOC) of Cu-rich devices is limited by the serious interfacial recombination. To suppress the interfacial recombination and improve the efficiency of Cu-rich devices, we co-evaporate CsF, In and Se at the surface of the Cu-rich absorber (Cs-In-Se-PDT). By this way, the compound of Cs-In-Se is formed at the absorber surface, which leads to the valence band energy, work function and the grain boundary recombination at the surface of the Cu-rich absorber decrease. This contributes to inhibiting the interfacial recombination. Especially, the tunneling assistant interfacial recombination can be suppressed significantly. Besides, the Cs-In-Se-PDT mainly changes the Cu content of the absorber surface, the advantage of Cu-rich in the interior of the absorber can still be maintained. After Cs-In-Se-PDT, the VOC of the Cu-rich device (CGI = 1.03 %) increases by about 90 mV, and the device efficiency also boosts from 12.7 % to 16.04 %.

Co,N,S co-doped hollow carbon with efficient oxidase-like activity for the detection of Hg2+ and Fe3+ ions

Most nanozymes have limited catalytic ability, and constructing high performance nanozymes is important and challenging. Metal-carbon hybrid materials obtained by integrating transition metals into carbon can not only generate rich active sites, but also enhance their electrical conductivity. Heteroatom doping is shown to be an efficient strategy to improve the catalytic activity of carbon-based nanozymes. Here, by taking advantage of the structural merits of MOFs-derived porous carbon materials combined with sulfur doping strategy, the Co,N,S co-doped hollow carbon material, i.e. Co-N/S-HCN, was fabricated by pyrolyzing a thiomalic acid (TA) modified zeolitic imidazolate framework (ZIF-67@TA) in a nitrogen atmosphere. It exhibits hollow dodecahedron shape with rich defects, high BET specific surface area of 240.75 m2/g and pore volume of 0.27 cm3/g. The electrochemical characterization reveals the doping of S reduces the charge transfer resistance of the Co-N-HCN, accelerates electron transfer rate, and finally boosts its catalytic activity. The Co-N/S-HCN shows superior oxidase-like activity and can convert colorless 3,3′,5,5′-tetramethylbenzidine (TMB), o-phenylenediamine and 2,2′-azo-bis (3-ethylbenzothiazolin-6-sulfonic acid) diammonium salt into visible color substrates without hydrogen peroxide. The oxidase-like activity of Co-N/S-HCN was 2.1 times that of Co-N-HCN. The quenching trials revealed the generation of O2•−, •OH and 1O2 during catalytic TMB oxidation by Co-N/S-HCN. The Co-N/S-HCN oxidase-like nanozyme exhibited good affinity to TMB with a Km value of 0.25 mM and Vmax of 4.19 × 10−7 M s−1. In terms of Soft-Hard Acid-Base principle, Hg2+ combines easily with the sulfur. Thus, the introduction of Hg2+ ions can restrain TMB oxidation catalyzed by Co-N/S-HCN, thereby inhibiting the color reaction. In addition, the addition of 8-hydroxyquinoline can restrain TMB oxidation catalyzed by Co-N/S-HCN, resulting in a decrease in absorbance at 652 nm. However, the color reaction recovers in the presence of Fe3+, resulting in an increase in absorbance at 652 nm. In terms of above fact, a colorimetric sensing platform for determining Hg2+ and Fe3+ ions was established and successfully used for detecting Hg2+ in water samples and Fe3+ in liquors. This work offers a different way to prepare nanozymes with efficient oxidase-like activity and is of great significance for detecting heavy metal ions in environmental and food samples.

Thermal atomic layer etching of VO2 using sequential BCl3 and SF4 exposures: Observation of conversion, ligand-exchange, and oxidation state changes

The thermal atomic layer etching (ALE) of VO2 was demonstrated using sequential exposures of BCl3 and SF4. The VO2 etch rate measured by quartz crystal microbalance investigations at 250 °C was 2.3 Å/cycle. The mass losses during individual BCl3 and SF4 reactions were nearly self-limiting versus BCl3 and SF4 exposures. The VO2 etch rates were also dependent on temperature and varied from 0.05 Å/cycle at 150 °C to 2.3 Å/cycle at 250 °C. Fourier transform infrared (FTIR) spectroscopy studies observed VO2 etching by monitoring the decrease in absorbance from V—O stretching vibrations in the VO2 film. The FTIR spectra during the initial BCl3 exposures on the VO2 film observed the growth of absorbance from B—O stretching vibrations from B2O3 and the concurrent loss of V=O vibrational features. These changes were consistent with BCl3 converting VO2 to B2O3. The FTIR difference spectra during subsequent SF4 and BCl3 reactions also observed the growth and loss of absorbance features that were attributed to F3V=O and V—F stretching vibrations, respectively. These changes indicate that SF4 fluorinates VO2 to form a VOF3 surface layer and then BCl3 undergoes ligand-exchange with VOF3 to volatilize the VOF3 surface layer as VOCl3. There was also evidence for conversion of VO2 to B2O3 during BCl3 exposures and then removal of B2O3 by SF4 exposures. In addition, quadrupole mass spectrometry (QMS) measurements observed that the SF4 exposures produced ion intensities for SOxFyClz products in oxidation states greater than 4+. These SOxFyClz products indicate that SF4 is being oxidized and acting as a deoxyfluorination reactant. Concurrently, the QMS analysis also monitored ion intensity for S8+, S7+, S6+, S5+, and S4+. These S8 electron impact ionization products argue that SF4 oxidation occurs concurrently with SF4 reduction. The QMS also observed ion intensities corresponding to VCl4+ and VOCl3+. The presence of VOCl3+ indicates that the oxidation state of vanadium has increased to 5+ in some of the volatile etch products. The QMS also detected trichloroboroxin (B3O3Cl3) during BCl3 exposures. B3O3Cl3 is a known etch product of B2O3 during BCl3 exposures. BCl3 can convert VO2 to B2O3 and then proceed to etch the converted B2O3. Thermal VO2 ALE using BCl3 and SF4 reveals the rich complexity of surface etching reactions that can proceed by multiple pathways including conversion, ligand-exchange, and oxidation state changes.

Preparation of a Flow Single-drop Extraction System for Educational Use Capable of the Simultaneous and Continuous Observation of Extraction Behavior and Absorbance Change

A portable flow single-drop extraction system was prepared as an educational tool for facilitating the connection between actual extraction behavior and theory. In this system, an aqueous dye solution is circulated through a ring-shaped extraction cell equipped with a droplet introduction unit and a flow cell for absorbance detection. The dye is extracted into a droplet in the extraction cell. This system enables simultaneous and continuous observation of the image of the droplet in the extraction cell and changes in absorption spectrum or absorbance over time on the same screen by using a USB camera. It was suggested that the material balance in the extraction can be calculated from the decrease in absorbance of the circulating dye solution and the absorbance of the droplet after the extraction.

Degradasi Pewarna Tekstil Remazol Violet 5R Dengan Metode Elektrooksidasi Menggunakan Elektroda Grafit

Remazol Violet 5R textile dye degradation experiment has been carried out by electrooxidation method using graphite electrodes. The electrooxidation device consists of a plastic tub with a size (p x l x h) = 20 x 20 x 25 cm which is equipped with an electric stirrer and graphite electrodes using a used battery anode. Graphite electrodes consist of 3 pairs arranged in parallel. This dye degradation experiment was carried out using a batch system (not continuous) with variations in stirring time of 15, 30, 45, and 60 minutes, while the other variables were fixed, namely the concentration of dye 100.24 mg/liter, electrolyte NaCl 2.06 g/liter, 12 V voltage, and a stirring speed of 250 rpm. The dye solution before degradation and after degradation was measured for absorbance using a UV-Vis spectrophotometer at the maximum wavelength, to determine the percentage decrease in absorbance and optimum contact time. The experimental results showed that the percentage decrease in absorbance was constant after a contact time of 30 minutes with an absorbance of 98.36%. This indicates that the optimum contact time for the degradation of Remasol Violet 5R dye is 30 minutes. From the experiments that have been carried out, it can be concluded that the electrooxidation method using graphite electrodes can be used as an alternative waste treatment method, especially in terms of removing dyes in textile industry wastewater.

A more selective and accurate method than indigo method for measuring dissolved ozone concentration (p-vinylbenzoic acid method)

Dissolved ozone concentration measurement is crucial for ozone treatment. In the most used conventional indigo method, the ozone concentration is measured by the decrease in absorbance due to the loss of the C–C double bond of indigotrisulfonic acid. However, measurement of ozone concentration is difficult when water contains substances that react with C–C double bonds other than ozone. To address this concern, we developed a novel breakthrough method to measure ozone concentration by measuring the p-formylbenzoic acid (p-FBA) produced after the reaction of p-vinylbenzoic acid and ozone. The formation of p-FBA was almost not caused by other substances (hypochlorous acid, hypobromous acid, permanganate ion and hydrogen peroxide), and its yield to ozone was maintained at 1 in river water, treated wastewater and seawater. In addition, the experimental error is smaller with the new method than with indigo. Furthermore, the new method does not require cumbersome calibration unlike indigo method because highly pure forms of p-FBA are commercially available. p-FBA can be separated by liquid chromatography and detected with highly sensitive ultraviolet and mass spectrometric detectors, and hence easily analyzed simultaneously with other substances. Our new method contributes to extensive ozone treatment and ozonation management.

Surface-enhanced Raman Scattering and Localized Surface Plasmon Resonance Detection of Aldehydes Using 4-ATP Functionalized Ag Nanorods

Formaldehyde, acetaldehyde, and benzaldehyde are well-known carcinogens affecting human health adversely. Thus, there is a need for efficient detection of these aldehydes. This work uses 4-aminothiophenol (4-ATP) functionalized silver nanorods (Ag NRs) to detect these three aldehydes. The detection mode includes localized surface plasmon resonance (LSPR) and surface-enhanced Raman scattering (SERS). The LSPR band of 4-ATP functionalized Ag NRs shows a linear decrease in absorbance with the increase in formaldehyde and acetaldehyde concentrations. A sensitivity of 0.96 and 0.79 ΔA/mM for formaldehyde and acetaldehyde were obtained. In the case of benzaldehyde, a nearly exponential decrease in absorbance with the increase in concentrations was observed. Above 98.4 μM concentration, the absorbance diminishes completely. The LoD for formaldehyde and acetaldehyde detection using LSPR is 33.8 and 24.6 μM, respectively. The SERS studies reveal that the 4-ATP binds to Ag NRs through both –SH and –NH2 groups and facilitates the inter-particle charge transfer process. The appearance of b2 modes of vibration for 4-ATP evidences this charge transfer process. In the presence of aldehydes, the change in the band shape, relative intensities, and band position were observed primarily in b2 modes of vibration, evidencing the modulation in the charge transfer process. These remarkable changes were seen in μM concentration of aldehydes. Therefore, detection of these aldehydes with 4-ATP functionalized Ag NRs using SERS is possible in concentrations as low as ~ 1 μM.

Superoxide intermediate in the oxygen reduction on a zinc hydroxide model corrosion product.

The inhibition of the electrochemical oxygen reduction reaction (ORR) by zinc corrosion products plays an important role in the corrosion protection of galvanized steel. Hence, the electrocatalytic mechanism of the ORR on electrodeposited zinc hydroxide-based model corrosion products was investigated by in situ and operando attenuated total reflection infrared (ATR-IR) spectroscopy, supplemented by density functional theory (DFT) calculations. Model corrosion products containing flake-like crystalline Zn5(NO3)2(OH)8 were cathodically electrodeposited on germanium(100) electrodes from a zinc nitrate precursor electrolyte. Substantial amounts of the films are non-crystalline, and their surfaces predominantly consist of zinc oxide and hydroxide species, as evidenced by x-ray photoelectron spectroscopy. ATR-IR spectra show a peak at 1180 cm-1 during cathodic currents in O2-saturated NaClO4 solution. This peak is assigned to a surface-bound superoxide, the only ORR intermediate detected. Absorbance from the intermediate increases with increasing cathodic current, indicating an increase in surface concentration of superoxide intermediates at larger ORR current densities. The zinc hydroxide ages in the experiments, most likely by a transformation into zinc oxide, consistent with the observed decrease in absorbance over time of the OH bending mode of zinc hydroxide at 1380 cm-1. This aging is a time-dependent chemical process, implying that pure chemical aging is important in actual corrosion products as well. DFT calculations of adsorbed superoxide yield a Zn-O bond length similar to the bond length in Zn-O, thus enhancing superoxide interaction with undercoordinated tetrahedral Zn2+ sites on the surface. Thus, such active sites catalyze the first reduction step in the ORR.

Influence of Comminution Methods and Air Exposure in the Production of Melissa officinalis Mother Tincture

Introduction: During the processing of fresh plants, prolonged exposure to the air can cause rapid oxidative changes, and this is further accelerated if they have large surface areas. These changes can ultimately lead to losses in valuable ingredients and deterioration of the final product. Consequently, in the food, cosmetics, and pharmaceutical industries, oxidation and the use of antioxidant conservatives are major considerations during processing and production. However, similar considerations are not currently made for herbal medicines. The differences in the UV-Vis spectra of several commercial herbal mother tinctures were investigated here to determine if the oxidation process occurred and should thus be considered during their production. Methods: The impact of air exposure on comminuted fresh Melissa officinalis and on the quality of the resulting mother tincture was evaluated using UV-Vis spectrophotometric analysis, antioxidant tests (potassium permanganate and FOLIN-Ciocalteu), and high-performance thin-layer chromatography. Results: A time-dependent decrease in phenolic compounds, UV absorbance, and antioxidant capacity of the Melissa officinalis mother tincture were observed. Specifically, the antioxidant capacity of ground Melissa officinalis in the resulting herbal mother tincture was reduced by 40.47% and 55.52% after 5 and 30 min of air exposure, respectively. Conclusions: The results indicate that the Melissa officinalis mother tincture is affected if its comminuted starting material is exposed to air during the manufacturing process and that this should be considered when producing fresh herbal medicine plant products in the future.

Preparation, Characterization and Antiradical Activity of Zinc Oxide Nanoparticles

Zinc oxide nanoparticles (ZnO NPs) have recently been studied as a multi-functional and multi-target nanomedicine for cancer treatment. They can be used not only as a nanocarrier for delivery of the chemotherapy drug but also as an antiradical agent due to their photo-catalytic and photo-oxidizing abilities. Our previous work showed a potential use of commercial-available ZnO NPs without and with carboplatin for the treatment of retinoblastoma. The aim of this work was to synthesize ZnO NPs having smaller particle size than the commercial ones, i.e., 100 nm average diameter, in order to improve the reaction time. ZnO NPs were prepared by a sol-gel technique and calcined with different calcination conditions. The structure and particle size of ZnO powders were characterized using an x-ray diffractometer and a particle size analyzer. Average nanoparticle sizes of 16.32 ± 1.64 nm were achieved at a calcination temperature of 300 degree Celsius and 1 hour holding time. The antiradical activity of prepared ZnO NPs in cooperation with ultraviolet irradiation was assessed using a putative model of cancer cells, i.e., 2,2(diphenyl-1-picryhydrazyl) radicals (DPPH*). An optical spectroscopy was used to detect the decrease in peak absorbance of the antiradical solution at a wavelength of 515 nm, which in turn can be used to calculate the percent remaining of DPPH*. The disappearance of DPPH* with respect to the reaction time revealed that prepared ZnO NPs (16.32 ± 1.64 nm) improved response time as compared with ZnO NPs (100 nm). Moreover, the effective ZnO concentrations to reduce the initial DPPH* concentration by 50%, also known as the EC50 value in the present study, is lower indicating the improvement of anti-proliferative activity when compared to the commercial ZnO NPs.

Sound energy absorbance changes in the elderly with presbycusis with normal outer and middle ear.

This study aimed to investigate the wideband tympanometry (WBT) findings in the elderly with presbycusis who have normal outer and middle ears according to otoscopic examination and traditional tympanometry, and to determine whether there is a relationship between the middle ear wideband absorbance value and the pure tone air-bone gap (ABG) observed especially at mid-high frequencies in the elderly. The study included 30 elderly with presbycusis (> 65years old, presbycusis group) and 30 healthy individuals (control group) between the ages of 18 and 55. Pure tone air conduction and bone conduction thresholds of all participants were determined and WBT was applied to all participants. Resonance frequency (RF), absorbance ratios at peak pressure (PPAR) and ambient pressure (APAR) values were analyzed. The RF value of the presbycusis group was lower than the control group (p < 0.05). APAR and PPAR values at 2000 and 4000Hz and mean absorbance values of the presbycusis group were lower than the control group (p < 0.05). APAR was higher at 500Hz in males than females (p < 0.05), but there was no difference between genders in RFs (p > 0.05). A moderate negative correlation was observed between ABG and both PPAR and APAR at 4000Hz in presbycusis group (p < 0.05). it was determined that there was a decrease in RF and absorbances at 2000 and 4000Hz in the elderly with presbycusis. Aging affects not only the inner ear but also the conduction mechanism of the middle ear. Our findings may be effective in a more accurate and reliable interpretation of WBT in the elderly with presbycusis.

A rapid and simple spectroscopic method for the determination of yeast cell viability using methylene blue.

Determination of cell viability is important in various microbiological studies. The microscopic method, counting dead cells stained by methylene blue (MB), has often been used for the determination of viability, although it is not efficient for the measurement of a large number of samples. Alternatively, some spectroscopic methods have been proposed to avoid tedious cell counting. One of these proposed methods detects the decrease in MB absorbance in the supernatant of cell suspension, because dead cells incorporate MB more efficiently than viable cells. However, at present, this spectroscopic method is rarely used due to its low throughput. Therefore, we devised a small-scale, rapid and simple method by improving several points as follows. (1) The peak wavelength of MB absorbance, 665 nm, was used to detect MB efficiently at the microtube scale. (2) The composition of the MB solution was improved by adding trisodium citrate. (3) The reaction time was shortened. And (4) the concentration ranges of both MB and cells, with which absorbance is linearly related to cell viability, were determined. The improved method enabled us to evaluate the dose-dependent toxicities of alcohols, antifungal/antimalarial quinacrine, and UV-C irradiation. The results were compatible with those of conventional microscopic counting and colony formation. The method would be applicable to automated determination and to various organisms such as bacteria and filamentous fungi which are difficult to be counted microscopically.

Influence of AlSi10Mg powder aging on the material degradation and its processing in laser powder bed fusion

This study investigates the impact of powder aging on the degradation of AlSi10Mg powder during processing in laser powder bed fusion. Powder aging as result of handling, continuous storage and recycling is a fundamental concern for aluminum alloys as it introduces oxygen to the feedstock material. In this work, the analysis of the powder properties, affected by laser exposure and the aging procedure, showed a change of chemical and morphological characteristics of the powders in virgin and aged conditions. The oxygen content in the powders appeared to have a significant effect on the powders' surface appearance and light absorbance, gradually deteriorating the processability of the powders with the increase of oxygen level. Optical microscopy and X-ray computed tomography were used to analyze the porosity distribution in the printed part samples, identifying the origin, size and location of the pores. A direct relationship between the pore occurrence in final parts and the oxygen content in the powders was observed, revealing a higher degree of porosity in the aged powder sample (6.5%) in comparison with the virgin state (3.16%). The evolution of mechanical properties in the part samples after laser processing and powder aging was also studied, demonstrating a rapid decrease of ultimate tensile strength and elongation from virgin condition to aged. • Change of AlSi10Mg powder properties with aging and laser processing was studied. • Powder aging induced a severe oxygen pick-up and a decrease of laser absorbance. • With the oxygen increase, pore occurrence in printed parts became more frequent. • Depending on powder condition, a notable change of tensile strength was observed.

Photoelectrochemical degradation of selected organic substances on Fe2O3 photoanodes: a comparison with TiO2.

The photoelectrochemical degradation of selected aromatic substances, acid orange 7 (AO7), salicylic acid (SA), benzoic acid (BA), and 4-chlorophenol (4-CP) was studied on hematite (α-Fe2O3) and compared with titanium dioxide (TiO2), both deposited as thin films on conducting substrates (FTO/glass). Batch type reactors were used under backside and front side illumination. Electrical bias was applied on the semiconducting electrodes, such that only valence band processes leading to oxidative pathways were followed. The initial Faradaic efficiency, f0, of degradation processes was determined from the UV-Vis absorbance decrease of the starting materials. f0 for 1mM AO7 degradation in 0.01M sulphuric acid was found to be 7.5%. When the pH of the solution was neutral (pH 7.2) or alkaline (pH 13), f0 decreased to 1.7%. For 1mM SA, f0 was 6.2% on hematite photoanodes and 6.1% on titanium dioxide. For 1mM benzoic acid and 4-chlorophenol, f0 was an order of magnitude lower, but only on hematite. This is ascribed to the lack of OH· radical formation on hematite, which seems to be essential for the photooxidation of these compounds.

A Simple and Rapid Spectrophotometric method for the determination of Iodate in table salt samples using Pyrogallol red dye

A simple and rapid spectrophotometric method for the determination of iodate in table salt samples has been standardized using the oxidation reaction of iodate with pyrogallol red dye in sulphuric acid medium. The determination of iodate was done by measuring the decrease in absorbance of pyrogallol red dye at 470 nm. A standard calibration curve was prepared, for iodate concentrations in the range of 0.05 µg mL-1 to5 µg mL-1. The effect of NaCl and Iinterference on iodate determination has been studied. The kinetics of the reaction between pyrogallol red and iodate has also been studied. The oxidation reaction was found to be first order with respect to iodate concentration. The method has been used for the determination of iodate in 10 different brands of locally available common salt samples.

A Simple and Rapid Spectrophotometric method for the determination of Iodate in table salt samples using Pyrogallol red dye

A simple and rapid spectrophotometric method for the determination of iodate in table salt samples has been standardized using the oxidation reaction of iodate with pyrogallol red dye in sulphuric acid medium. The determination of iodate was done by measuring the decrease in absorbance of pyrogallol red dye at 470 nm. A standard calibration curve was prepared, for iodate concentrations in the range of 0.05 µg mL-1 to5 µg mL-1. The effect of NaCl and Iinterference on iodate determination has been studied. The kinetics of the reaction between pyrogallol red and iodate has also been studied. The oxidation reaction was found to be first order with respect to iodate concentration. The method has been used for the determination of iodate in 10 different brands of locally available common salt samples. Key Words: Iodate, Table salt, Pyrogallol

A Simple and Rapid Spectrophotometric method for the determination of Iodate in table salt samples using Pyrogallol red dye

A simple and rapid spectrophotometric method for the determination of iodate in table salt samples has been standardized using the oxidation reaction of iodate with pyrogallol red dye in sulphuric acid medium. The determination of iodate was done by measuring the decrease in absorbance of pyrogallol red dye at 470 nm. A standard calibration curve was prepared, for iodate concentrations in the range of 0.05 μg mL-1 to5 μg mL-1. The effect of NaCl and Iinterference on iodate determination has been studied. The kinetics of the reaction between pyrogallol red and iodate has also been studied. The oxidation reaction was found to be first order with respect to iodate concentration. The method has been used for the determination of iodate in 10 different brands of locally available common salt samples