Determination of trace impurities in chromium matrices after separation from Cr(III) using the oxalate form of anion exchanger.
A method has been developed for the separation and determination of a set of 11 impurities from chromium matrices using oxalate form of Amberlite IRA 93. Due to slower kinetics of formation of the anionic complex, Cr(III) passed in the effluent while impurities forming strong complexes rapidly are retained on the exchanger. The adsorption of impurities of interest is found to be uniform in pH range 2-6. The adsorbed impurities are eluted with 2 mol l(-1) HNO(3) and determined by inductively coupled plasma-optical emission spectrometer (ICP-OES). The percentage recoveries of Al, Bi, Cd, Co, Cu, Fe, Mn, Ni, Pb, Ga and Zn are in the range 88-101% and separation of matrix is >99.9%. The method has been applied for the analysis of two samples namely CrCl(3).6H(2)O and Cr. The R.S.D. of the method is 5-6% at >10 microg g(-1) level and approximately 15% at <1 microg g(-1) level. The process blank values are in the range sub-microg g(-1) and detection limits are in ng g(-1) range.
Venkateswarlu
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National Centre for Compositional Characterisation of Materials, B.A.R.C., E.C.I.L. (P.O.), Hyderabad, India.
Sahayam
A C
AC
Chaurasia
S C
SC
Mukherjee
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T