Miniaturisation of a matrix separation/preconcentration procedure for inductively coupled plasma mass spectrometry using 8-hydroxyquinoline immobilised on a microporous silica frit

A comparison has been performed on miniaturised matrix separation/preconcen tration procedures using packed micro-columns of imminodiacetate (IDA) chel ating reagents and an 8-hydroxyquinoline (8-HQ) micro-column. Commercially available IDA reagents, Prosep and Muromac, were packed into micro-columns and 8-HQ has been immobilised on a novel microporous silica structure. Thes e have been successfully utilised for the determination of several trace el ements in complex matrix samples. The miniaturised matrix separation/precon centration procedures have been developed to reduce sample analysis time. A microconcentric nebuliser in the ICP-MS permits the multielement analysis on a smaller volume of solution leading to a reduction in reagent consumpti on and a more efficient procedure. Preparation of the micro-columns is desc ribed along with optimisation of the procedures with respect to the variabl es buffer concentration, buffer pH, eluent acid concentration and reagent f low rates. Sample analysis times are compared for both miniaturised systems . Analysis times of 3.0 min for the IDA column and 2.3 min for the 8-HQ col umn are reported. Calibrations showed good linearity with correlation coeff icients of 0.999-0.9998 for IDA columns and 0.999-0.9997 for 8-HQ column fo r a range of analytes. Recoveries ranging from 91-102% for IDA columns and 96-105% for the 8-HQ column are reported for a range of elements. The metho d was validated by the analysis of estuarine (SLEW-1) and coastal (CASS-2) certified reference materials. Good agreement between the certified and ref erence values was obtained for the materials.