铜合金中锌的络合滴定,以铜铅锌三元素的连续测定法及用氰化钾掩蔽,甲醛解蔽法应用最广。由于氰化钾有剧毒,我们制订了不用氰化钾的分析方法。试样用硝酸分解,加硫代硫酸钠掩蔽铜、铋及部分镉,氟化钠掩蔽锡(Ⅳ)、铝、铁(Ⅲ)、钛等,用六次甲基四胺调节 pH 至5.5～6.0,用二甲酚橙指示剂,EDTA直接滴定。铅、镍的共同滴定,可用其他方法测得含量从总量中减除。对于含锰试样需进行一次分离(可在强氨性溶液中加少量过氧化氢,生成 MnO(OH)_2沉淀而过滤除去),不宜求合量。因为锰在 pH5.0～6.0络合不稳定。砷、锑、钙、镁、硅、磷等在上述条件下不 Copper alloy zinc complex titration, continuous determination of copper, lead, zinc and three elements with potassium cyanide masking, formaldehyde decontamination method is the most widely used. Since potassium cyanide is highly toxic, we have developed an analytical method that does not use potassium cyanide. The sample is decomposed with nitric acid, and sodium thiosulfate is used to mask copper, bismuth and some cadmium, sodium fluoride to conceal tin (IV), aluminum, iron (III) 6.0, with xylenol orange indicator, EDTA direct titration. Lead, nickel common titration, other methods can be measured by the total amount of subtraction. For manganese-containing samples need to be separated once (in a strong ammonia solution plus a small amount of hydrogen peroxide, generating MnO (OH) _2 precipitate and filtered to remove), should not seek the amount. Because manganese complexed in pH5.0 ~ 6.0 unstable. Arsenic, antimony, calcium, magnesium, silicon, phosphorus, etc. not under the above conditions