Page 15 of Ion Chromatography for power plants by Metrohm AG

determination of anions in the primary circuit of nuclear power plants for this application the «mic-6 advanced» is used a modular anion system with chemical suppression sample preconcentration and matrix elimination extended by matrix neutralization 800 dosino metrosep i trap 1 and transfer tubing a total of five «misp» techniques are used · inline calibration · inline cation elimination · inline neutralization · inline sample preconcentration · inline matrix elimination the composition of the sample corresponds to the water used in the primary circuit and contains 2.5 g/l boron added in the form of boric acid this high concentration makes inline matrix elimination necessary this is carried out by rinsing the anion preconcentration column with ultrapure water before the sample is injected calibration for anion determinations the calibration values are selected so that the whole of the expected concentration range is covered the linearity of the inline calibration is excellent the coefficients of correlation for all anions are 0.9999 anions calibration level of inline calibration ­ concentrations given in ppb ­ g/l no ion level 1 level 2 level 3 level 4 no of sample loop switchings 1 2 5 10 volume 10 l 20 l 50 l 100 l 1 fluoride 2 glycolate 3 acetate 4 formate 5 chloride carbonate 500 6 nitrite 7 bromide 8 nitrate 9 phosphate 10 sulfate sample concentrations corresponding to a preconcentration volume of 2000 l 1 fluoride 2 glycolate 3 acetate 4 formate 5 chloride carbonate 2.5 5.0 12.5 25.0 6 nitrite 7 bromide 8 nitrate 9 phosphate 10 sulfate column metrosep a supp 7 ­ 250 6.1006.630 eluent sodium carbonate eluent sample standard level 1 2 3 and 4 concentration ppb ­ g/l 15

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