Usage

GB5009.34-2022 "Determination of sulfur dioxide in food"; 2015 and 2020 editions of the Chinese Pharmacopoeia for the detection of sulfur dioxide residues in Chinese medicinal materials and decoction pieces

GB5009.34 and the 2015 edition of the Chinese Pharmacopoeia stipulate three methods for detecting sulfur dioxide: acid-base titration, spectrophotometry (food)/gas chromatography (traditional Chinese medicine), ion chromatography, etc. Spectrophotometry/gas chromatography and ion chromatography have the advantages of high sensitivity and strong specificity, but the instruments and equipment are expensive, which is not conducive to the promotion and use of grassroots food and drug inspection systems;

The acid-base titration method has the advantages of simple equipment and low cost. It is a statutory test method stipulated in the national food standard and pharmacopoeia. However, since only glass instrument devices are used to describe this method, the purchase, assembly and implementation of the entire set of equipment still need to be continuously improved. For example: (1) In addition to the glass instrument device, it is also necessary to equip and assemble a magnetic stirrer, electric heating jacket, titration platform, nitrogen device with flow meter, etc. Many units feel that it is cumbersome to purchase too much equipment and difficult to assemble and implement, so they cannot carry out this test method; (2) The assembled devices are varied. During use, there are problems such as unstable nitrogen flow rate, uneven heating, easy leakage, easy boiling, and easy to be affected by cooling water source, which directly affect the test results, such as poor parallelism and low recovery rate; (3) The work efficiency is low. The current equipment uses a single-unit device, which is difficult to process multiple samples at the same time. It is time-consuming and laborious to test multiple batches of medicinal materials at the same time.