Improved detection method for sulfur dioxide

Abstract

The invention provides an improved detection method for sulfur dioxide. The detection method comprises the following steps: treating a sample; placing the sample into a special digestion bottle for Kjeldahl determination, putting the digestion bottle on an azotometer, inserting the lower end of an absorption tube into a lead acetate absorption liquid in an iodine number flask, adding a hydrochloric acid solution, then immediately capping a plug, carrying out heating and distillation and carrying out blank control test during detection; adding concentrated hydrochloric acid and an iodine standard solution into a distilled fluid, placing the obtained mixture in a dark place for a reaction for 2 min, rapidly titrating an excess iodine liquid in the distilled fluid by using a sodium hyposulfite standard solution, adding a starch indicator when the distilled fluid has a light yellow color after titration and terminating titration when a blue color turns into colourless; and calculating the content of sulfur dioxide in the sample according to the consumed amount of sodium hyposulfite. According to the invention, a Kjeldahl determination apparatus is used to replace a manually-built simple distillation apparatus, so the method is simple and easily practicable, reduces system errors and improves accuracy of analysis results.

Description

technical field [0001] The invention relates to an improved sulfur dioxide detection method. Background technique [0002] Sulfite and its salts are commonly used bleaching agents in our country. In many food processing processes, sulfonation and sulfite solution impregnation are often used for bleaching. Sulfur dioxide, the main component of bleaching agents, can cause sore throats and stomach pains for eaters. Adverse reactions such as local discomfort and certain damage to the liver. [0003] Distillation is commonly used to detect sulfur dioxide. The traditional distillation method uses an electric furnace to heat a round-bottom flask and connect a condenser to cool it down. It takes time and effort to set up this device, and the temperature is not easy to control, which makes the experiment cumbersome and increases the system error. Contents of the invention [0004] In view of this, the present invention proposes an improved sulfur dioxide detection method, which is...

AI Technical Summary

Problems solved by technology

[0003] The distillation method is commonly used to detect sulfur dioxide. The traditional distillation method uses an electric furnace to heat a round bottom flask and connect a condenser tube to cool down. It takes time and effort to build this device, and the temperature is not easy to control, which makes the experiment cumbersome and increases the system error.