Free Sulfite Test Strips, 10-500 ppm [Vial of 50 Plastic Strips]

The Free Sulfite Test Strip is used to detect sulfite ions in water-based solutions, measuring in increments of 10, 50, 100, 250, and 500 ppm. Various types of sulfites can be tested with this strip: sulfite, bisulfite, and metabisulfite. When testing foods for sulfite content, such as wine, it is important to realize that the sulfite present can be either free or bound. The strip detects free sulfite only, the pH needs to be adjusted to 12 to get an accurate reading for total sulfites (free plus combined). Please contact us before buying if you intend to use it for testing red wine or something for total sulfites so we can provide you more information. Instructions: Immerse the test strip into the solution and swirl 3 times. Remove the strip and compare to the color chart after 15 seconds. NOT recommended for red wine (color pigments in the wine cause interference with the strip). NOT recommended for people with a sulfite sensitivity / allergy to test for allergens (the strips are not sensitive enough to detect the low level of free sulfites).