Simultaneous Determination of Sub jig g-1 Levels of Impurities in High Purity Iron by Inductively Coupled Plasma-Atomic Emission Spectrometry after Circulation of Eluant through Anion Exchange Resin Mini-Column

Boron, Mo, Nb, Sn, Ta, W and Zr were separated from an iron matrix using a horizontal mini-column of an anion exchange resin. The flow of solutions through the mini-column was controlled by a peristaltic pump. The elements adsorbed on the resin were simultaneously eluted by the circulation of an eluant and determined by inductively coupled plasma-atomic emission spectrometry. Quantitative recoveries were obtained for all 7 elements in the acid-soluble fraction and for 5 elements (not B or Sn) in the acid-insoluble fraction. A part of B in the acid-insoluble fraction was lost during the ashing and the fusion but the loss was compensated by using the calibration solutions prepared with the same procedure as that for the samples. A 500-fold enrichment was obtained using this preconcentration system compared with an ordinary sample solution of 0.5 g/ 100 cm3. The proposed method was applied to the simultaneous determination of sub μg g-' levels of impurities in high purity irons.