鲁米诺-H_2O_2-Cu(Ⅱ)化学发光法测定镍(Ⅱ)

Determination of nickel(Ⅱ) by luminol-hydrogen peroxide-copper(Ⅱ) chemiluminescence method

基于Ni(Ⅱ)能置换出Cu(Ⅱ)-EDTA络合物中的Cu(Ⅱ),与鲁米诺-H2O2-Cu(Ⅱ)化学发光体系相偶合,建立了测定Ni(Ⅱ)的置换偶合反应流动注射化学发光法测定Ni(Ⅱ)的新方法。考察了Cu(Ⅱ)-EDTA络合比、反应介质与pH、氧化剂的选择及其浓度以及鲁米诺浓度对体系相对发光强度的影响,并采用酒石酸掩蔽剂消除了干扰组分对测定的影响。在最佳的实验条件下,该方法测定Ni(Ⅱ)的线性范围为5.0×10-8～5.0×10-6 g/mL,检出限为2.0×10-8 g/mL(3σ)。对环境水样中的镍(Ⅱ)进行测定,其结果同原子吸收光谱法的测定值相一致,相对标准偏差为3.7%～4.6%。

Nickel  could replace copper  in Cu -EDTA complex and then coupled with luminol-H2O2-Cu  chemiluminescence system.On the basis of this,a new determination method of nickel  was established by replacement coupling reaction flow injection chemiluminescence method.The effects of Cu -EDTA complex ratio,medium and pH of reaction,the selection of oxidant and its concentration,and luminol concentration on relative chemiluminescence intensity were investigated.Interference ions were effectively masked by the addition of tartaric acid.Under the optimal experimental conditions,linear range of this method was 5.0×10-8-5.0×10-6 g/mL for nickel ,and detection limit was 2×10-8 g/mL（3σ）.The proposed method has been applied to the determination of nickel  in environmental water samples,and the results were consistent with those obtained by atomic absorption spectrometry with relative standard deviations（RSD） of 3.7 %-4.6 %.