Untersuchungen zur Gleichwertigkeit von Analysenverfahren — Flie\injektionsanalyse und DIN-Verfahren bei der Chloridbestimmung in der Wasseranalytik

Summary

The German standard method for the determination of chloride in water, waste water and sludge, laid down in the norm DIN 38405-D 1–2, is based on the titration with AgNO₃ and potentiometric detection for the range 7–140 mg/l chloride. In order to investigate the equivalence of a more rapid method, flow injection analysis with different detection methods (photometric, potentiometric and by atomic absorption) is applied. Thirty samples of water of different types (waste, tap, surface and mineral water) are analysed and the results are examined by a statistical test, which, according to the norm DIN 38402, part 71, is based on orthogonal regression. The test shows that the results obtained with the FIA-methods are equivalent to those from the German standard method. The three flow injection systems mentioned have a 10–36-fold higher sample frequency and a lower (down to 1/1000) sample and reagent consumption. Therefore, these FIA-methods are superior to the actual German standard method.