摘要
本文报道在0.1M亚硝酸钠,1.5×10^(-3)M的1,2-丙二胺,pH9.0—9.5底液中铬在—1.76伏处(对饱和甘汞电极)产生-催化波,测定范围在0.1ng/ml内,铬的浓度与导数波高成良好线性关系,测定下限为8×10^(-10)M(相当于0.04ng/ml)。经实验证明,在1,2-丙二胺-亚硝酸盐或硝酸盐两体系中,铬都在—1.76伏处产生催化波,因此,可认为铬的催化机理可能与文献[3]报道的在CyDTA-NO_3体系中三价铬产生催化波的机理相似即: Cr^(6+)+3e—→Cr^(3+); Cr^(3+)+y—→Cr^(3+)—y; Cr^(2+)—y+e—→C^(2+)—y; Cr^(2+)—y+NO_3~—→Cr^(3+)—y+No_2^-其中:y代表1,2-丙二胺。将自来水进行简单的前处理后,可以直接应用本法测定水中六价、三价铬的含量以及水中的总铬量。
The chromium's catalysis wave has been measured at—1.76V(vs, SCE) in a base solution which consists 1.5×10^(-3)M 1,2-diaminepropalyene 0.1M natrium nitrite, pH9～9.5; The lowest limit is 8×10^(-10)M(as 0.04ng/ml) with high sensitivity, and the wave height of oscilloscope derivative has an excellent linear relation with the concentration of chromium salt in the range of 0～lng/ml.The electrode pocedure is assumed through the experiments as following: Cr^(6+)+3e→Cr^(3+) Cra^(3+)+y→Cr^(3+)-y Cr^(3+)-y+e→Cr^(2+)-y Cr^(2+)-y+NO_3^-→Cr^(3+)-y+NO_2~_ Where y represents 1,2-diaminepropalyene. After a very simple preceeding treatment to tap water, the amount of Cr^(6+) and total amount of chromium in it may be directly measured by using the present method, and the amount of Cr^(3+) is also obtained.
出处
《四川环境》
北大核心
1989年第4期22-28,共7页
Sichuan Environment
关键词
1
2-丙二胺
铬
催化波
水污染
Catalytic polarographic
Chromium
1,2-diaminepropalyene
Natrium nitrite.
