Abstract: Adsorption properties of a fast iminodiacetate-agarose adsorbent, IDA-Novarose, with a capacity of 120-140 µmol/ml were studied for pre-concentration of eight transition elements. A FIA-ICP-PLES system was used in the study. It was shown that 0.3 mL of the adsorbent, packed in a column, can quantitatively accumulate Cr3+, Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+ and Cd2+ from standard solutions in the pH range between 4 and 8 at high loading flow rates (10-80 ml/min). The rate of adsorption was studied in batch experiments and found to be fast and equal for the divalent metal ions but relatively slow for accumulation of Cr3+ and Fe3+. Online buffering of acidified samples improved the accumulation of metal ions from synthetic samples spiked with humic acid. Quantitative uptakes were observed for most of the studied metals. The accumulation of Cr3+ was found to be quite sensitive to the ionic strength and some loss of inert complexes of Fe3+ was also observed. The method was applied to the analysis of certified riverine water (SLRS-3), a tap water and a lake water. With few exceptions the results obtained by ICP-AES after pre-concentration agreed well with the certified concentrations and results found by ICP-MS.

Abstract: An earlier method (cf. Lundstrom, Ibid., 1982, 29, 291) for the determination of Br- was modified to include flow injection spectrophotometric measurement and a smaller ion-exchange column for pre-concentration. Sample solution containing BrO3- and IO3- obtained by oxidation of Br- and I- is mixed with a carrier solution containing 0.2 M NaCl, 1 M NaClO4, 0.05 M Na2SO4, 0.09 M NaH2PO4 and 0.01 M Na2HPO4 before detection at 355 nm. Calibration graphs are rectilinear for 1 to 15 µM and the limit of detection is 0.7 µM for both IO3- and IO3- plus BrO3-. The injection frequency is 60 h-1. Results were compared with those obtained by the original method and agreed to within ±1.5%. The method was applied to water samples.