氢化油中含镍量的测定

Determination of nickel in hydrogenated oil

对显色剂丁二酮肟与镍在水相中的显色反应进行了研究,优化了显色条件,比较了显色试剂的不同加入顺序,试剂加入顺序应依次为:标准液、丁二酮肟、过硫酸铵、氢氧化钠,用此加入顺序时,标准曲线线性范围较宽(0 1mg·L-1～10mg·L-1),相关系数为0 99974,显色反应快且稳定。比较了测定氢化油中镍的3种预处理方法,确定了以氯仿为溶剂的酸提取最佳预处理方法,用丁二酮肟水相直接分光光度法测定氢化油中镍的相对标准偏差为4 5%,回收率为103 0%。

The coloring reaction of dimethyl glyoxime with nickel in aqueous solution was studied.The conditions for coloring reaction were optimized.Different sequences of adding reagents were compared,and the optimal sequeuce was identified as:standard solution,dimethyl glyoxime,ammonium persulfate and sodium hydroxide.Following such sequence,the coloring reaction was quick and stable with wide linear range(0.1 mg·L^(-1)～10 mg·L^(-1)) in the standard curve and correlation factor of (0.999 74.)Three kinds of pretreatment methods were compared for the determination of nickel in hydrogenated oil.The appropriate pretreatment was identified as to dissolve the oil sample in chloroform and to extract with acid.