![]() In the analysis of welding fumes, the modified DPC method gave the same results as the laborious and less sensitive carbonate method. To isolate chromium, a mixture of chromite and sodium carbonate is heated in air to form sodium chromate, iron(III) oxide, and carbon dioxide. For chromic acid mist, the DPC method and AAS analysis were shown to give the same results. A comparison was made of the DPC method, acidic dissolution with atomic absorption spectrophotometric (AAS) analysis, and the carbonate method. If not breathing, give artificial respiration. If breathed in, move person into fresh air. Show this safety data sheet to the doctor in attendance. First-aid measures 4.1 Description of necessary first-aid measures General advice. However, carbonate salts present some technological issues such as a high melting temperature (around 400 ☌), high cost and also certain corrosive potential. Field samples were taken from two different industrial processes-manual metal are welding on stainless steel without shield gas and chromium plating. chromium(3+),carbonate: 5 : none : 100: 4. Carbonates such as nitrates possess a high heat capacity and great energy density, and therefore, require a smaller tank volume. Replacement of sulfuric acid by a sodium acetate buffer (pH 4) as a leaching solution prior to analysis with the diphenylcarbazide (DPC) method is suggested and is demonstrated to be necessary in order to avoid reduction. In this paper, the stability problems arising from the reduction of hexavalent to trivalent chromium during sampling, sample storage, and analysis are discussed. In view of the serious health effects of hexavalent chromium, the problems involved in its sampling and analysis in workroom air have been the subject of much concern.
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