DETERMINATION OF FE(II) AND FE(III) IN SMALL SAMPLES BY MICROBORE ION CHROMATOGRAPHY AND PHOTOMETRIC, ATOMIC-ABSORPTION SPECTROMETRY AND TOTAL-REFLECTION X-RAY-FLUORESCENCE DETECTION

Iron(II) and iron(III) are determined after separation on an ion chromatographic column by various detection systems. ''On-fine'' detection was achieved by the use of a photometer with a flow cell of 0.8 mul; for ''off-fine'' detection, graphite furnace atomic absorption spectrometry or total-reflection X-ray fluorescence were used. The applicability of the methods is shown for standard solutions and atmospheric samples. As a typical result, 50 mug/l of iron can be determined in a 10 mul sample with a microbore ion chromatograph-photometer and atomic absorption system and 40 mug/l of iron in a microbore ion chromatograph-total-reflection X-ray fluorescence combination.