Studies on the origin of sulphur in wool : II. A cuprous mercaptide method for the determination of cystine or cysteine

Abstract

1. A. method for the micro-determination of cystine in biological or plant material has been described. The dried material is hydrolysed with 40 per cent. sulphuric acid the cystine precipitated by cuprous chloride as the cysteine cuprous mercaptide. The cysteine content of this is determined by the modified Sullivan method. 2. The interfering colouring matter is automatically eliminated. 3. The method is quick and comparatively easy.