A facile spectrophotometric method for the determination of periodate using azure B

Abstract

Foi desenvolvido um método simples, rápido e sensível para a determinação de periodato em amostras de água de rio e em solução. O método é baseado na reação do periodato com iodeto em meio ácido, com liberação de iodo. O iodo liberado diminui a intensidade da cor violeta do azure B, medida em 644 nm. O decaimento da absorbância é diretamente proporcional a concentração de periodato e obedece a lei de Beer na faixa de 0,2 -5,5 μg mL -1 . A absortividade molar, a sensibilidade de Sandell e os limites de detecção e de quantificação encontrados foram 1,09x10 5 L mol -1 cm -1 , 1,75x10 -3 μg cm -2 , 0,07 μg mL -1 and 0,20 μg mL -1 , respectivamente. As condições ótimas de reação e os parâmetros analíticos foram avaliados. O efeito de íons interferentes é descrito. O método proposto foi aplicado com sucesso na determinação de periodato em amostras de águas de rio e em solução.A simple, rapid and sensitive spectrophotometric method has been developed for the determination of periodate in solution and river water samples. The method is based on the reaction of periodate with iodide in an acid medium to liberate iodine. This liberated iodine bleaches the violet color of the azure B and is measured at 644 nm. This decrease in absorbance is directly proportional to the periodate concentration and obeys Beer's law in the range of 0.2 -5.5 μg mL -1 . The molar absorptivity, Sandell's sensitivity, detection limit and quantitation limit of the method were found to be 1.09 X 10 5 L mol -1 cm -1 , 1.75 X10 -3 μg cm -2 , 0.07 μg mL -1 and 0.20 μg mL -1 respectively. The optimum reaction conditions and other analytical parameters were evaluated. The effect of interfering ions on the determination is described. The proposed method has been successfully applied to the determination of periodate in solutions and river water samples.Keywords: periodate determination, spectrophotometry, azure B IntroductionThe determination of iodine compounds, particularly periodate, I(VII) is important in organic chemistry, biology and life sciences, but it is rather difficult to determine I(VII) at low concentrations. Periodate is used for the oxidation of different inorganic, organic compounds and catalytic applications at trace levels. 1-6 Therefore simple, rapid, sensitive and accurate method is required for the determination of trace amounts of periodate in different samples.Many methods have been reported for the determination of periodate, such as thin layer chromatography, 7 capillary zone electrophoresis, 8 pulse polarography, 9 fluorometry 10 Chemeluminiscence. 3 Some of the reported chromogenic reagents for the spectrophotometric determination of periodate are 5,5-dimethyl-1,3-cyclohexanedione bisthiosemicarbazone monohydrochloride, 11 amodiaquine dihydrochloride, 12 ferroin, 13 o-dianisidine, 14 4-bromo-N,N'-bis ( 2-hydroxypropyl)-o-phenylenediamine, 15 2,2'-azinodi (3-ethylbenzothiazol-6-sulphonate). 16 Of these reagents, few are reported to be carcinogenic while few others are less selective, less sensitive, time consuming and suffer fr...

Photochromic properties of the molecule Azure A chloride in polyvinyl alcohol matrix

“…First time, azure B has been used as achromogenic reagent for the spectrophotometric determination of product. The proposed method, which is simple and rapid, offers the advantages of sensitivity and wide range of determinations without the need for M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 7 extraction or heating and it does not involve any stringent reaction conditions [8]. Excited electronic states of molecular systems can be calculated by TD DFT and TD HF methods [9][10][11][12][13][14][15].…”

A Rapid and Simple Spectrophotometric Determination of Traces of Chromium (VI) in Waste Water Samples and in Soil samples by using 2-Hydroxy, 3-Methoxy Benzaldehyde Thiosemicarbazone (HMBATSC)

“…The usefulness of the proposed method was tested by determining Chromium (VI) concentration in samples of circulating industrial waste water [9] and in soil samples [10], previously certified by atomic absorption spectrometry. Recovery tests for the analyzed samples were satisfactory (about 98% to 101%) with relative error of + 0.1 to 1.5 ( Table 2).…”

Phenotiazinium Dyes as Photosensitizers (PS) in Photodynamic Therapy (PDT): Spectroscopic Properties and Photochemical Mechanisms

“…Physico-chemical properties of Azure B have motivated the employment of Azure B as a chromogenic reagent for the spectrophotometric determination of several compounds, which are relevant to biological and environmental chemistry such as periodate [ 105 ]. This cited method is simple and rapid, offering advantages of sensitivity and wide range of determinations, without involvement of any stringent reaction conditions, being successfully applied to the determination of periodate in solution and in several river water samples.…”