Toshio Hidaka

Determination of Residual Chlorine in Foods by Head Space Gas Chromatography

An analytical method was developed for quantitative determination of residual chlorine in foods using head space gas chromatography.The principles of the proposed method are as follows. Phosphate buffer solution of pH 7.0 and potassium cyanide solution were placed in a vessel for head space analysis, a sample was added, and the resultant mixture was left standing in the vessel (covered with a lid) for 30 minutes. Cyanogen chloride formed therein was determined by ECD-GC. The values of residual chlorine in tap water measured by the present method were compared with those obtained by the o-tolidine colorimetric method. The respective values were quite consistent. The determination limit was 0.1μg/g.Analysis of 67 specimens of vegetables and processed fish and shellfish products available in the market revealed 14.0μg/g and 11.6μg/g of residual chlorine in two specimens of soybean sprouts.