Microdetermination Of Arsenic Research Articles

Micro-determination of arsenic in aqueous samples by image scanning and computational quantification

Arsenic is highly toxic in all of its forms found in natural groundwater. An improved method for the estimation of inorganic arsenic at low levels (μg L−1) in water has been proposed. The method involves the generation of arsine in a specially designed cell by borohydride reduction of arsenite (AsO21−). The resulting arsine is passed through a filter paper pre-dipped in mercuric bromide solution giving a yellowish brown complex. The color intensity of the spots is calculated by scanning the spotted paper and analyzing the image using specially designed software. The method was found to be effective at trace levels having a linear response at the concentration range 2–20μg L−1 (8–80ng). The detection limit of the proposed method is 1 μg L−1 (4 ng) which can be reduced further by making some modifications to the apparatus. The method was successfully applied to the analysis of synthetic samples and field samples of water.

Microdetermination of arsenic(III) and osmium(VIII) through osmium-thiourea reaction

Osmium-thioureau reaction is slow under conditions described in earlier methods. In the present study it has been observed that arsenic(III) catalyzed the reaction. Based on this, qualitative and quantitative methods are described for the determination of both osmium and arsenic. Interference study of 30 ions showed they do not interfere.

Macro- and microdetermination of arsenic(III) using potassium permanganate as an oxidant in acid medium in presence of fluoride ions

A method is described for the determination of trivalent arsenic. It depends on the oxidation of As 3+ to As 5+ in H 2SO 4 solutions with KMnO 4 in presence of fluoride ions under the following conditions: Acidity: 0.9–3.6 N H 2SO 4 in presence of 50 ml of 2% NaF; sodium fluoride: 25–75 ml of 2% solution/100 ml; temperature: should not exceed 60 °C; amounts of As 3÷, 0.0165–92.42 mg.

Microdetermination of Arsenic with Silver Diethyldithiocarbamate. : Studies on the Absorber Tubes and the Quality of Zinc

In the micro-determination of arsenic using the silver diethyldithiocarbamate method, there have been observed some differences in the relationship between the shape of absorber tube and absorbance at 520 mμ and this point was examined. 1. Even by the use of the same absorber tube, there have been observed some differences in the absorbancy at 520 mμ according to the conditions of each experiment, so that it was necessary to make the calibration curve at every experiment. 2. There was no difference in experimental values when using an apparatus which could insure a more uniform rate of flow of gas into the absorbent. 3. As a result of examining the quality of zinc, a more precise result was obtained by the use of copperized zinc than untreated one. 4. Using the above described method, some biological materials were tested and good results were obtained.

Microdetermination of arsenic by a precipitation titration

The procedure described is suitable for the determination of As(III) in macro or micro amounts. The sample is dissolved in 0.1 M Na 2HPO 4 in the presence of hydrochloric acid. After oxidation with bromine and removal of excess bromine with Na 2SO 3, the phosphate and arsenate is titrated with magnesium chloride in the presence of ammonia-ammonium chloride and ethanol. MgNH 4PO n · 6H 2O and MgNH 4AsO 4 · 6H 2O are precipitated during the titration. Thymolphtalexon is used as the indicator. Sulfur compounds, ethanol, acetone, formaldehyde, phenol, and other oxidizable substances do not interfere. Ferric and aluminum salts are masked with triethanolamine. Calcium and Magnesium ions are sequestered with EDTA.

New microdetermination of arsenic by the application of internal electrolysis: C. Yoshimura, Nippon Kagaku Zasshi, 78, 1586-88 (1957)

New microdetermination of arsenic by the application of internal electrolysis: C. Yoshimura, Nippon Kagaku Zasshi, 78, 1586-88 (1957)

Microdetermination of arsenic by relfectance spectrophotometry: I. Kawashiro, T. Okado, and S. Kato, Eisei Shikenjo Hôkoku, 75, 15–18 (1957)

Microdetermination of arsenic by relfectance spectrophotometry: I. Kawashiro, T. Okado, and S. Kato, Eisei Shikenjo Hôkoku, 75, 15–18 (1957)