GB/T 35950-2018 in English

Titration Method:The process of using a reagent solution of known concentration to react with the substance to be tested to the chemical stoichiometric point through a chemical reaction. In this standard, sodium hydroxide is used as the standard solution for titrating the generated sulfuric acid.

Ion Chromatography:A high-performance liquid chromatography technique suitable for the separation and detection of anions/cations. In this standard, potassium hydroxide solution is used as the eluent to separate sulfite and bisulfite through an anion exchange column.

Recovery Rate: refers to the ratio of the actual measured amount to the theoretical value after adding a known amount of the substance to be tested to the sample. The recovery rates of the titration method and ion chromatography in this standard are between $83.5\%\sim91.7\%$ and $87.8\%\sim107.1\%$, respectively, indicating the reliability and accuracy of the method.

Implementation Recommendations

1. **Laboratory Configuration Requirements**: - Equipped with advanced analytical equipment (such as ion chromatograph, titration device, etc.) to meet the needs of high-precision detection. - Reagents and materials must meet analytical purity standards to ensure the accuracy of experimental results.

2. **Operator Training**: - It is recommended to conduct systematic training for laboratory personnel to master the operating procedures and precautions of the two determination methods. - Strengthen the understanding of the principles of titration and ion chromatography, especially the skills in complex sample processing.

3. **Data recording and analysis**: - It is recommended to use professional data analysis software for result calculation and statistics to ensure compliance with the formula requirements in the standard (such as formula (1) and formula (2)). - Regularly calibrate the instrument and review the experimental data to ensure the stability of long-term detection.