Determination of Twenty-four Elemental Impurities in Sodium Oleate by ICP-MS
A microwave digestion-inductively coupled plasma mass spectrometry(ICP-MS)method was established for the simultaneous determination of twenty-four elemental impurities in sodium oleate.The results showed that it was linear for twenty-four elemental impurities in the corresponding mass concentration ranges(r>0.997 0).The average recoveries(n=9)were 87.04%-114.7%,with the RSDs of less than 9.8%.The eighteen batches of sodium oleate samples from four manufacturers were tested,and the Ni element contents in three batches of samples from one manufacturer were close to or exceed its control threshold,while the remaining twenty-three elements were far below the control threshold.The established method has high sensitivity and good accuracy,which can be used for trace control of twenty-four elemental impurities in sodium oleate.