| abstract |
4-Pyrrolylpyridine, a new anion sensor, shows a noticeable loss of color when sodium sulfite is added to aqueous solvents. Various anions have been tested, including halides, phosphates, sulphates and hydroxide, but all solutions remain unchanged except sulphite, which is bleached. The invention relates to a method for determining the exact concentration of sulfites in a consumer product. The test is sensitive over a wide range of sulfite amounts, ranging from 0.84 ppm to over 10,000 ppm, and is accurate with a standard deviation of ± 0.01 ppm. |