A Double-Label Radioactive Tracer Analysis of the Retention of Selected Fats on Cotton and its Relation to Yellowing

Abstract

A double-label radioactive tracer analysis was developed to determine the comparative retention of representative sebum components on cotton fabric after repeated soiling and laundering and to determine whether the presence or absence of clay significantly affected the retention of the fats. Retention was related to chain length, polarity, unsatura tion, and presence of clay. The yellowness of cotton soiled with pairs of fats was measured in the presence and absence of clay. Clay contributed significantly to the yellow color. When fat alone was present, there was no significant increase in yellowing until after the fifth wash for oleic acid and triolein. An interaction between the fats and clay caused additional yellowing which was possibly due to greater uptake of clay by entrapment in a fatty matrix and/or to catalysis of oxidation reactions of unsaturated fats by metal ions present in kaolinite clay. '