Elemental Analysis of Iron and Steel by Solid-phase Extraction/ICP-MS Using a Cation Exchange Extraction Disk

Abstract

A simple pretreating method which consists of solid phase extraction using cation exchange extraction disk was tried for the determination of trace elements in iron and steel samples by means of inductively coupled plasma mass spectrometry (ICP-MS). The sample of 0.100 g was dissolved by nitric acid, subsequently adding 8 cm³ of 10w/v% ethylenediaminetetraacetic acid disodium salt (EDTA) solution as masking agent for the iron matrix. The sample solution was adjusted by the dilution with water to pH 1.8 or more and poured into the extraction disk. The target elements retained in the extraction disk were then eluted using 10 cm³ of 3 kmol/m³ nitric acid. Quantities of the obtained target elements were determined using ICP-MS. Highly sensitive quantification was established for 6 trace elements in iron and steel, and for Ca, Mn, Mg, Ba, Tl and Sr with the following detection limits [3σ; ng/g (ppb)]: Ca: 4.75, Mn: 0.26, Mg: 0.40, Ba: 0.014, Tl: 0.033 and Sr: 0.11. This method is extremely easy, is rapid, the amount of the reagent used is a little, and a free skill and the zero emission are achieved.