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Abstract: A rapid, simple, accurate, and highly selective spectrophotometric method is proposed for the determination of periodate in water samples. This method is based on the reaction of methylene green with periodate in the presence of iodide. The decrease in the absorbance of methylene green is used to monitor the reaction spectrophotometrically at 613nm. Under the optimum conditions, periodate could be determined in the concentration range 0.18–6.0μgmL−1. The detection limit for the method is 0.010μgmL−1. The influence of various foreign species was studied, and it was found that iodate did not interfere with the determination even in the presence of 200-fold of periodate. The relative standard deviations for six replicate determinations of 0.30, 0.50, 1.0, 1.5, 4.0, and 5.5μgmL−1 of periodate were 3.33, 2.0, 1.6, 1.33, 0.50, and 0.55%, respectively. The proposed method was applied to the determination of periodate in water samples and indirect determination of ethylene glycol in antifreeze and glycerol in vegetable oil via malaprade reaction, and satisfactory results were obtained. [Copyright &y& Elsevier]

A flow injection (FI) system is described for the sequential determination of periodate and iodate based on their reaction with iodide at pH 3.5. Two sample plugs were injected into the same carrier stream sequentially. One injection is for the iodate determination and the other for the sum of iodate and periodate determination. For iodate determination, molybdate solution buffered at pH of 3.5 was used for selective masking of periodate. The influences of reagent concentrations were studied by a univariable method and the influence of FI manifolds was studied using univariable and simplex method. Periodate and iodate can be determined in the range of 0.050–5.0 and 0.050–10 μg/ml, respectively. The 3σ limit of detection was 0.030 and 0.050 μg/ml for periodate and iodate, respectively. The proposed method has been applied for the sequential determinations of periodate and iodate in water samples. [Copyright &y& Elsevier]

A simple and efficient flow-injection method was used with good results to determine periodate and iodate in water. The method is based on the reaction of periodate or iodate with pyrogallol red in sulfuric acid media. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of pyrogallol red at 470 nm. The chemical and FIA variables were established using the univariate and simplex optimization methods. The calibration curve was linear over the concentration ranges of 0.8–73.0 and 2.0–100.0 μM for IO4− and IO3−, respectively. The detection limits were 0.7 and 1.0 μM for IO4− and IO3−, respectively. The sample throughput was 20±5 h−1. The influence of potential interfering ions in the determination of the anions was tested. The relative standard deviations for 4.20 and 5.73 μM periodate and iodate were 1.8 and 2.2%, respectively. [ABSTRACT FROM AUTHOR]