Method for measuring content of exogenous sulfur dioxide in food and device for preparing liquid to be measured for measuring method

The invention discloses a method for measuring the content of exogenous sulfur dioxide in food and a device for preparing liquid to be measured for the measuring method. The method comprises the following steps: (1) mixing a sample to be detected with an acidic reaction solution at room temperature for reaction, and collecting sulfur dioxide generated by the reaction; (2) introducing the collected sulfur dioxide into the sulfur dioxide absorption liquid to obtain a liquid to be detected; and (3) analyzing the to-be-detected liquid, and calculating the content of exogenous sulfur dioxide in the food according to an analysis result. According to the method, the to-be-detected sample does not need to be distilled, the extraction process is carried out at room temperature, the extraction time is short, endogenous sulfur-containing metabolites in the shiitake mushroom samples do not participate in the reaction to separate out sulfur dioxide, and only the exogenous sulfite added in an additive form reacts and is ex