RAPID AND ACCURATE DETERMINATION OF MANGANESE IN WASHING POWDERS USING ALKALI FUSION AND INDUCTIVELY-COUPLED PLASMA TECHNIQUES

Procedures using lithium metaborate fusion were developed for the dete rmination of manganese in commercially available washing powders. Bulk samples were homogenized and ground to reduce particle size, fused wi th LiBO2 and the resulting melt was dissolved in dilute nitric acid, T he method was initially compared with results obtained after nitric ac id leaching, Approximately 45 samples can be prepared in a working day , making this a rapid procedure, Sub-mu g g(-1) detection limits were obtained by both ICP-AES and ICP-MS, Results from the acid leaching ga ve RSDs better than 10%; however, the lengthy procedure (several hours per sample) was dropped in favour of the more rapid fusion procedure, Experiments showed that a mean recovery of 99.5 +/- 11% could be obta ined, The intra-sample precision (RSD) was typically better than 1% an d the inter-sample precision, demonstrated by the analysis of replicat e preparations, was < 8% and was limited by sampling errors, Quality c ontrol data collected over al month period showed a reproducibility of 2.3% (RSD).