title: Determination of sulfite in foods by headspace liquid chromatography.
abstract: Sulfite was determined in a variety of foods by liquid chromatography (LC) after the samples were mixed with a solution containing mannitol, FeSO4, and Na2HPO4, adjusted to pH 11, and left to stand for 15 min at room temperature. An aliquot of the mixture was placed in a headspace vial and mixed with 50% H3PO4. After 15 min, a portion of the headspace was removed with a syringe containing LC mobile phase without acetonitrile. The syringe was shaken and an aliquot of the solution was analyzed on an anion exchange column with a mobile phase of 0.03M methane sulfonate (pH 10.8) containing 5% acetonitrile. Sulfite was detected amperometrically (glassy carbon electrode) at +0.7 V. The method was successfully compared to the FDA-modified Monier-Williams procedure for a variety of foods. Minimum detectable levels were about 1 microgram/g, based on a 15 g sample.
authors.affiliation: Health Protection Branch, Bureau of Chemical Safety, Ottawa, Ontario, Canada.
authors.forename: J F
authors.initials: JF
authors.lastname: Lawrence
authors.forename: R K
authors.initials: RK
authors.lastname: Chadha
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D033364:Decapoda; D005504:Food Analysis; D005512:Food Hypersensitivity; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008460:Meat / Q000032:analysis; D013447:Sulfites / Q000032:analysis*; D014675:Vegetables / Q000032:analysis; D014920:Wine / Q000032:analysis
chemical_list: D007202:Indicators and Reagents; D013447:Sulfites