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采用微分脉冲溶出伏安法，建立了氨水‐氯化铵体系中，氨水掩蔽 Z n2＋，丁二酮肟（DM G ）络合Ni2＋，不经预分离测定痕量的Cu2＋、Pb2＋、Cd2＋和Ni2＋的方法。本体系可消除大量Z n2＋对N i2＋、C d2＋的干扰。在起始电位―0.80 V、终止电位―0.1 V、富集电位―0.85 V、富集时间100 s、扫描速率0.015 V／s、加入0.5 mL氨水‐氯化铵溶液的条件下，Cu2＋、Pb2＋、C d2＋的溶出峰电位分别为―0.28、―0.47、―0.63 V ，质量浓度分别在2.0×10－6～1.0×10－3、1.6×10－6～6.6×10－3、2.3×10－6～1.1×10－2 g／L范围内与其峰电流呈良好的线性关系，方法检出限分别为8.9×10―8、8.1×10―7、2.1×10―7 g／L。不更换溶液，再向溶液中加入0.5 mL DMG溶液、0.6 mL氨水，在起始电位―0.90 V、终止电位―1.2 V、富集电位―0.80 V、富集时间40 s、扫描速率0.015 V／s的条件下，N i2＋的溶出峰电位为―1.03 V ，质量浓度在1.0×10―6～5.6×10―4 g／L范围内与其峰电流呈良好的线性关系，方法检出限为4.6×10―7 g／L。溶液中可能存在的常见离子不干扰Cu2＋、Pb2＋、Cd2＋和Ni2＋的测定。采用标准加入法测定混合标准溶液中的Cu2＋、Pb2＋、Cd2＋和 Ni2＋，其结果的相对标准偏差（RSD ，n＝6）为0.075％～1.8％；回收率为90％～109％。方法可用于硫酸锌电解液、中性上清液等实际样品的测定，其中中性上清液的测定结果与电感耦合等离子体原子发射光谱法（IC P‐A ES ）测定结果基本吻合。

T he determination method of trace Cu2+ ,Pb2+ ,Cd2+ and Ni2+ by differential pulse stripping vol‐tammetry without pre‐separation was established .In ammonia water‐ammonium chloride system ,Zn2+was masked by ammonia water ,and Ni2+ was complexed by dimethylglyoxime (DMG) .This system could eliminate the interference of much Zn2+ to the determination of Ni2+ and Cd2+ .The stripping peak poten‐tial for Cu2+ ,Pb2+ and Cd2+ was -0.28 ,-0.47 and-0.63 V ,respectively ,under the following experi‐mental conditions :the initial potential was -0.80 V ,the terminal potential was -0.1 V ,the accumula‐tion potential was -0.85 V ,the accumulation time was 100 s ,the scanning rate was 0.015 V/s ,and 0.5 mL of ammonia water‐ammonium chloride solution was added .The mass concentration in range of 2.0 × 10-6 -1.0 × 10-3 ,1.6 × 10-6 -6.6 × 10-3 and 2.3 × 10-6 -1.1 × 10-2 g/L for Cu2+ , Pb2+ and Cd2+showed good linear relationship to the peak current. The detection limit was 8.9 × 10―8 ,8.1 × 10―7 and 2.1 × 10―7 g/L ,respectively. If the solution was not replaced ,and 0.5 mL of DMG and 0.6 mL of ammo‐nia water were added into solution ,the stripping peak potential for Ni2+ was -1.03 V under the following conditions :the initial potential was -0.90 V ,the terminal potential was -1.2 V ,the accumulation po‐tential was -0.80 V ,the accumulation time was 40 s and the scanning rate was 0.015 V/s .The mass con‐centration of Ni2+ in range of 1.0 × 10―6 -5.6 × 10―4 g/L showed good linear relationship to the peak cur‐rent .The detection limit of method was 4.6 × 10-7 g/L .The common ions in solution did not interfere with the determination of Cu2+ ,Pb2+ ,Cd2+ and Ni2+ .The content of Cu2+ ,Pb2+ ,Cd2+ and Ni2+ in mixed standard solution was determined by standard addition method . The relative standard deviations (RSD ,n=6) were between 0.075% and 1.8% .The recoveries were between 90% and 109% .The pro‐posed method was applicable for the determination of actual samples of zinc sulfate electrolyte and neutral liquid supernatant .The found results of neutral liquid supernatant were consistent with those obtained by inductively coupled plasma atomic emission spectrometry (ICP‐AES) .