Use of Muromac A-1 chelating resin for determination of copper and molybdenum in seawater by atomic absorption with on-line preconcentration

Muromac A-1 chelating resin is used to preconcentrate trace metals (copper and molybdenum) in seawater. A miniature column (4-7 mu l) packed with resin and a home-made automatic on-line preconcentration system for graphite furnance atomic absorption spectrometry (GFAAS) were used. This preconcentration system was modified from a Perkin-Elmer AS-40 autosampler by mounting a Muromac A-1 microcolumn near the tip of the autosampler capillary. The preconcentration procedure was performed by using a four-way distribution valve and a programmable controller. A sample volume of only 20-200 mu l was required for determining copper and molybdenum in seawater. The calibration graph method was used; the detection limits for copper and molybdenum were 0.05 ppb and 0.25 ppb respectively. The sample throughput was 18-26 h(-1). The accuracy of the method was confirmed by the analysis of certified reference saline waters. (C) 1997 Elsevier Science B.V.