Coupling on-line preconcentration by ion-exchange with ETAAS: A novel flow injection approach based on the use of a renewable microcolumn as demonstrated for the determination of nickel in environmental and biological samples

摘要: Abstract A novel way of exploiting flow injection/sequential injection (FIA/SIA) on-line ion-exchange preconcentration with detection by electrothermal atomic absorption spectrometry (ETAAS) is described and demonstrated for the determination trace-levels nickel. Based on use a renewable microcolumn incorporated within an integrated micro FI-system, column loaded defined volume small beads SP Sephadex C-25 cation-exchange resin subsequently exposed to metered amount sample solution. However, instead eluting retained analyte from organic resin, are along 30 μl carrier (buffer) solution transported via air segmentation directly into graphite tube, where they ashed during pyrolysis atomization process. The ETAAS performed in parallel process ensuing sample. An enrichment factor 72.1, limit 9 ng l−1, sampling frequency 12 h−1 were obtained 150 s loading time at rate 12 μl s−1 (corresponding 0.72 ml min−1). relative standard deviations 3.4%. procedure was validated nickel contents two certified reference materials human urine