摘要 |
FIELD: analytical methods in industrial sanitation. ^ SUBSTANCE: method envisages bringing solution to be analyzed into contact with potassium bichromate, sulfuric acid, and mercuric sulfate, ageing resulting mixture and allowing it to cool to ambient temperature, adding ferroin indicator, titration of excess of potassium bichromate with 0.125 n. Moor salt solution, and calculating chemical oxygen demand value from amount of Moor salt consumed in the titration. Method is characterized by that initial solution is preliminarily homogenized until diameter of suspended particles therein become as large as 0.03 mm, after which solution is allowed to stay for 4 min. ^ EFFECT: reduced determination inaccuracy. |