摘要
提出了直接稀释-电感耦合等离子体质谱法(ICP-MS)同时测定母乳中钒、铬、锰、钴、镍、铜、锌、砷、硒、锶、钡、钼、镉、锡、锑、汞、铅等17种元素含量的方法.取母乳0.5 mL,用含2%(体积分数)硝酸和0.01%(体积分数)四甲基氢氧化铵的0.01%(体积分数)曲拉通X-100溶液定容至10 mL,涡旋混匀,以转速4 000 r·min-1离心5 min,将上清液用0.45 µm水相滤膜过滤,在动能歧视(KED)模式下采用ICP-MS测定滤液中上述17种元素的含量,在线加入含6 µg·L-1钪、锗、铑、铋的混合内标使用液.结果表明:各元素的质量浓度在一定范围内与所对应的信号强度与内标元素信号强度比呈线性关系,检出限(3s)为0.019～0.768 µg·L-1;方法用于分析美国国家标准参考材料,除锌元素外,其他元素的测定值均在认定值的不确定度范围内,并且日内和日间的变异系数均小于13%;按照标准加入法进行回收试验,回收率为81.3%～119%.
Abstract
A method for simultaneous determination of 17 elements including vanadium,chromium,manganese,cobalt,nickel,copper,zinc,arsenic,selenium,strontium,barium,molybdenum,cadmium,tin,antimony,mercury,and lead in breast milk by inductively coupled plasma mass spectrometry(ICP-MS)with direct dilution was proposed.0.5 mL of breast milk was taken and made its volume up to 10 mL with 0.01%(volume fraction)Triton X-100 solution containing 2%(volume fraction)nitric acid and 0.01%(volume fraction)tetramethyl ammonium hydroxide.The mixture was vortex mixed evenly,and centrifuged at a rotational speed of 4 000 r·min-1 for 5 min.The supernatant solution was passed through a 0.45 µm water phase filter membrane,17 elements in the filtrate were determined by ICP-MS in kinetic energy discrimination(KED)mode,and 6 µg·L-1 mixed internal standard solution,including scandium,germanium,rhodium,and bismuth was added online.As shown by the results,linear relationships between the ratios of the corresponding signal intensity to the internal standard signal intensity and mass concentrations of elements were found in definite ranges,with detection limits(3s)in the range of 0.019-0.768 µg·L-1.This method was used for analysis of American national standard reference materials,and the determined values of other elements except zinc were found within the uncertainty range of the certified values,with coefficients variation of intra-day and inter-day less than 13%.Test for recovery was made by the standard addition method,giving results in the range of 81.3%-119%.
基金项目
中央财政经费资助项目(131031108000150003)
维普
万方数据