A Procedure for Determination of Total Sulfur and Inorganic Sulfate Content of Food Stuffs

A procedure for determination of total sulfur and a procedure for determination of inorganic sulfate content of the edible portions of foodstuffs common to the American diet were investigated. The test food was New York State variety green cabbage. Total sulfur (as sulfate) was determined by the Parr sulfur bomb atomic absorption spectrophotometric method. The determination was made with and without added sodium sulfate standard. Good recovery and precision, 101.4 ±2.3%, were obtained by this method. An attempt was made to determine total sulfur (as sulfate) as the sum of the four sulfur components: inorganic sulfate, organic sulfate, ethereal sulfur and amino acid sulfur. The sum of these components was 11.2% higher than the total sulfur obtained by the Parr sulfur bomb atomic absorption spectrophotometric method. Therefore, replications and a recovery experiment were completed on the method for fractionation and determination of inorganic sulfate. The determinations were made with and without added sodium sulfate standard; recovery and precision were 101.2 ±6.9%. Replications and recovery experiments were not completed on the methods for fractionation and determination of organic sulfate, ethereal sulfur and amino acid sulfur.