METHOD FOR PHOTOMETRIC DETERMINATION OF NITRATES IN WATER SUPPLY SOURCES

摘要

The invention relates to photometric analysis of water solutions in ultraviolet light and can be used for determination of nitrates in natural waters. A method for the determination of nitrates in water supply sources consists in preliminary addition of (1.0-2.0)∙10M of peroxydisulfate to the sample tested, with boiling at pH 2-3 during 4-6 min, addition of ethyl alcohol, at molar ratio peroxydisulfate:ethyl alcohol equal to 1:( 40÷50), with following sample boiling during 4-5 min and with measurement of optical density of solution in ultraviolet light. The method makes it possible to determine content of nitrates in natural waters with high color (surface, water-main water, underground water), with high sensitivity (0,5 mg/dm), with high accuracy (relative error is 2-10 %).