Qualitative detection of N-nitrosodiethanolamine in cosmetic products

A relatively quick and simple procedure is described for the detection of N-nitrosodiethanolamine in various cosmetic products. The procedure is based on the irreversible formation of p-nitroso-N,N-dimethylaniline which has a bright yellow colour in basic solution. The compound is formed following extraction of the cosmetic, photolysis of the aqueous extract and the addition of N,N-dimethylaniline to photolysed extract.