Operation and Calculation

Take 1.0ml of the sample into a 10ml colorimetric tube, add water to the 10.0ml mark, cover and mix well. Take 1.0ml and place it into another colorimetric tube or test tube. Add 4 drops of color reagent and titrate with total acid measuring solution. Shake a few times after each drop of measuring solution. When the solution turns red (dark vinegar turns brownish red), record the total number of drops and calculate based on each drop being equivalent to 0.3% grams of total acid. For example, if only 6 drops of measuring solution are consumed, the total acid content of this sample is 6 × 0.3%=1.8% grams. According to national standards, when preparing vinegar, at least 8 drops should be added. If the solution turns red (dark vinegar turns brownish red), it indicates that the total acid content of the prepared vinegar is qualified; To brew vinegar, drop at least 12 drops. If the solution turns red (dark vinegar turns brownish red), it indicates that the total acid content of the brewed vinegar is qualified. The less measuring solution is consumed when measuring samples, the lower the acetic acid content. This method is used for rapid on-site measurement. For samples whose measurement results do not meet the national standard values or label labeling values, the measurement should be repeated three times. For samples whose measurement results differ only 1-2 drops from the standard or labeling amount, caution should be taken and they can be sent to the laboratory for precise determination.

Complete set of reagents

1 bottle of titration solution for rapid detection of total acetic acid in vinegar

1 bottle of color reagent for rapid detection of total acetic acid in vinegar

1 10ml colorimetric tube

10 large straws

precautions

1. A large straw is a graduated straw used to measure samples

2. Immediately clean the test tube, straw, etc. after each use for future use

3. The validity period of the reagent is six months, please use it within the validity period.