The assessment was organized and implemented by the Quality and Technical Supervision Bureau of Guangxi Zhuang Autonomous Region. In accordance with the relevant provisions of the Administrative Measures for the Accreditation of Inspection and Testing Institutions (Order No. 163 of the General Administration) and the Implementation Measures for the Verification of Laboratory Competence (Announcement No. 9 of the National Accreditation Administration in 2006), the laboratory of Heshan Center for Disease Control and Prevention used the TA-98 (automatic) visible spectrophotometer of Shenzhen Sinsche Technology Co., Ltd, The blind sample was determined according to the Determination of Ammonia Nitrogen Nessler's Reagent Spectrophotometry (HJ535-2009), and the test results were satisfactory.
So, what precautions should be taken for blind sample assessment of ammonia nitrogen? Based on many years of testing and R&D experience, sinsche technical engineers list the following points:
1. The environment for testing the ammonia nitrogen project must be ammonia-free;
2. Soak ammonia nitrogen containers with 1+9 hydrochloric acid and wash them out before use;
3. Use ammonia-free water;
4. Pay attention to reagent blank;
5. When the water sample needs to be filtered, the filter paper needs to be cleaned repeatedly. It is recommended to centrifuge or filter with filter membrane;
Post time: Mar-20-2023