Gas-Liquid Chromatographic Determination of Nitrate and Nitrite in Cheese, Ham, Fish Sausage, Cod Roes, and Salmon Roes

Publisher Website
Google Scholar
Abstract
The 2,4-xylenol method was modified and a gas-liquid chromatographic (GLC) method was developed for nitrate and nitrite determinations in several foods. Either a flame ionization (FID) or an electron capture detector (ECD) can be used. Proteins and fats are removed from warm alkaline water with zinc sulfate and filtered. The filtrate is evaporated to dryness, redissolved in water, and reacted with 2,4- xylenol in the presence of sulfuric acid to form 6-nitro-2,4-xylenol. Interfering chlorides are precipitated with silver sulfate and the nitroxylenol is extracted with hexane, concentrated, and injected. Nitrite in the nitrate is distilled at pH 5, collected in alkaline solution, and dried. The residue is oxidized to nitrate with permanganate in the presence of sulfuric acid, and then chromatographed in the same manner as nitrate. Recoveries from several foods were 83-100% for nitrate and 80-100% for nitrite. The limit of sensitivity was 0.1 ppm for both residues.

This publication has 0 references indexed in Scilit: