Preliminary Experiments for Analysis of Methylguanidine in Foods

Abstract

For analysis of methylguanidine (MG) which can be nitrosated to highly mutagenic and carcinogenic methylnitrosocyanamide, preliminary experiments were made to determine the most appropriate analytical procedures. Extraction of sample materials with a mixture of concentrated hydrochloric acid and 5% solution of ethanol in acetone (2:1000) and column chromatographic fractionation of the extract, first using microcrystalline cellulose as adsorbent and a mixture of concentrated hydrochloric acid and ethanol (2: 1000) as eluant, and then using Amberlite CG-50 resin as adsorbent and 1.6N sodium hydroxide as eluant were thought to give an adequate isolation of MG from other related compounds. Amount of MG was then quantitatively determined by Sakaguchi reaction. The isolated MG was confirmed by paper chromatography of the above fractions using a mixture of butanol, acetic acid, and water (4:1:2) as a developer. For gas chromatographic examination, conversion of methylguanidine to its pyrimidine derivative by heating with anhydrous sodium carbonate and acetyl acetone in n-amyl alcohol was tried but the conversion was not well quantitative.