CHEMICAL OXYGEN DEMAND (CODcr)-RESULTS OBTAINED BY THE CLOSED TUBE METHOD AND THE STANDARD PROCEDURE ARE IN AGREEMENT
A comparison was made between the Nordic standard and the small-scale closed tube method for the determination of CODcr. The closed tube method studied follows the standard procedure except that the sample and reagent volumes are one fifth of those in the standard. The results from the two methods are in good agreement and the reproducibility, recovery and limit of determination all correspond. The closed tube method is well suited for routine work also from the aspect of worker safety and environmental protection.