高锰酸盐指数标准样品测定正确度影响因素及对策OA

Permanganate index is a key indicator for evaluating water pollution levels,a mandatory item in surface water and groundwater monitoring,and also a critical assessment index for verifying the competence of laboratories and inspection bodies.In accordance with the newly issued standard HJ 1445-2026"Water Quality—Determination of Permanganate Index-Sodium Oxalate Reduction Acidic Titration",this study systematically explored the influencing mechanisms of experimental location,water used for tests,concentrations of potassium permanganate and sodium oxalate standard solutions,standard sample concentration,heating duration,and acid dosage on the trueness of permanganate index determination in standard samples.The core technical differences between HJ 1445-2026 and GB/T 11892-89 and their impacts on measurement results were emphatically compared.Targeted optimization countermeasures and suggestions compatible with the new standard HJ 1445-2026 were proposed,providing a scientific basis for laboratories in different regions to carry out standard sample determination in compliance with this method.This ensures the accuracy,consistency and compliance of monitoring data,and lays a solid foundation for water environmental quality assessment and pollution control.