Study of interference in the flame atomic absorption spectrometric determination of lithium by using factorial design

• DOI: 10.1007/s002160051412
• Publication Date: 2002-08-25T07:47:25Z
• Authors: B. Baraj; Luis F. H. Niench...; Ronaldo D. Trapaga; Rosiléa G. França; Valbona Cocoli; Daniel Robinson
• Keywords: 01 natural sciences; 0105 earth and related environmental sciences

The severe interference of a number of metallic ions found in brines, marine sediments and sea water in the determination of lithium is demonstrated. Calcium, iron and sodium significantly depressed the absorption signal on lithium in an air/acetylene flame. Aluminium, magnesium and strontium up to 1500, 1000 and 200 μg/mL, respectively, showed no interference in the determination of lithium under the same conditions. Potassium produced some suppression of the lithium signal at levels in excess of 1500 μg/mL. Experimental data were examined using the factorial design method. Interference was demonstrated in two synthetic samples (models of “brine” and “marine sediments” ) and natural marine sediment. It was possible to eliminate all interferences using a higher temperature (nitrous oxide/acetylene flame). In addition, by using the standard addition method the interference disappeared, which confirmed the interference as a proportional systematic error.