Abstract
Methods for the analysis of N-nitrosodiethanolamine (NDELA) in cosmetics and raw materials were studied by conventional analytical instruments.
The colorimetric method was attempted first, but pretreatment of sample was not complete, we couldn't obtain a good result.
Gas chromatography combined with electron capture detectior (ECD-GC) was useful and sensitive method for determining low level of NDELA in cosmetics. The detection limit was about 10ppb.
NDELA in triethanolamine was directly analysed by high pressure liquid chromatography and UV detection (UV-HPLC). NDELA in cosmetics was first separated by normal phase HPLC followed by quantitation using reverse phase HPLC. The detection limit was about 200ppb. This method which eliminates or minimizes sample preparation and extraction/concentration steps should be applied to many cosmetics.
