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电镀液中镍的分析一般采用氰化钾容量法及二甲基乙二醛肟重量法。前者终点难掌握容易引起误差;后者耗时较长,都不适于日常检验之用。由于络合分析化学的发展,近年来应用于电镀溶液分析的较多。有用磷酸铵沉淀镁后,再用EDTA测定镍的,但镁铵盐易溶于过量试剂,很难得到正确结果。有用EDTA-电位法,利用不同电位来滴定镍镁的,但限于设备推广较难。考虑到镍电镀液中含有镁,尤里斯脱利用镍、镁与EDTA络合的相应pH值分别为2.7及7.5的关系,提出在pH=5时用EDTA-FeCl_3间接法测定镍,于另一试样中在pH=10时测定镍、镁总量后,从而计算镍镁含量。结果满意,但仍须取两个试样,分别测定。我们采用在pH=
Analysis of nickel plating bath generally use potassium cyanide capacity method and dimethyl glyoxal weight method. The former difficult to grasp the end point easily lead to errors; the latter takes a long time, are not suitable for routine testing purposes. Due to the development of complexation analysis chemistry, it has been applied to the analysis of electroplating solution more in recent years. Use of ammonium phosphate precipitation of magnesium, and then the determination of nickel by EDTA, but magnesium ammonium salt soluble in excess reagent, it is difficult to get the correct result. Use EDTA-potential method, the use of different potentiometric titration of nickel-magnesium, but limited to the promotion of equipment more difficult. Taking into account the nickel plating solution containing magnesium, Jurisprudence with nickel, magnesium and EDTA complexation of the corresponding pH value of 2.7 and 7.5, respectively, at pH = 5 with EDTA-FeCl_3 indirect method for the determination of nickel, in another The sample was measured at pH = 10 nickel, magnesium total, to calculate the nickel-magnesium content. Satisfactory results, but still need to take two samples were measured. We use at pH =