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本文介绍了取40毫升水样,控制在0.24当量浓度的硝酸磷酸酸度下,用二苯碳酰二肼直接显色,即可测得六价铬;如果将40毫升水样控制在0.24当量浓度的硝酸磷酸酸度下,用高锰酸钾氧化,在尿素存在下,再用亚硝酸钠还原过剩之高锰酸钾并煮沸,然后用二苯碳酰二肼显色,测出的吸光度减去六价铬的吸光度后,即可测得三价铬。实践证明,此法快速、准确、简便。分析结果令人满意。此文还列出了三价铬的直接显色、六价铬的直接显色,三价铬及六价铬同时存在时的回收试验,显色液酸度对测定的影响试验及水样分析等试验数据。
This article describes the take 40 ml of water samples, control of 0.24 equivalent concentration of nitric acid phosphate acidity, with diphenylcarbazide direct color, you can measure hexavalent chromium; if the 40 ml of water control in 0.24 eq Of nitric acid phosphate acidity, with potassium permanganate oxidation, in the presence of urea, and then sodium nitrite excess potassium permanganate and boil, and then diphenylcarbazide color, measured absorbance minus After the absorption of hexavalent chromium, trivalent chromium can be measured. Practice has proved that this method is fast, accurate and easy. The result of the analysis is satisfactory. The article also lists the direct color development of trivalent chromium, the direct color development of hexavalent chromium, the recovery test when trivalent chromium and hexavalent chromium exist together, the influence of the acidity of the color reagent on the determination and water sample analysis Test Data.