Determination of N-nitrosodiphenylamine as a Carcinogenic compound in cosmetics by gas chromatography flame ionization detector

In this study, a simple analytical method based on gas chromatography coupled with flame ionization detector (GC-FID) was developed for the determination of N-nitrosodiphenylamine in cosmetics. N-nitrosodiphenylamine (NDPA) is classified in Group 1A carcinogenic compound [1]. The nitrite in water cosmetic sample had reacted with diphenylamine and produced N-nitrosodiphenylamine [2]. A simple and rapid ultrasound-assisted dispersive liquid–liquid microextraction method coupled with GC-flame ionization detection was developed for determination of NDPA in cosmetics samples including, cream makeup, shampoo and lipstick. An ultrasound-assisted field was applied to accelerate the formation of the fine cloudy solution using small volume of disperser solvent, which markedly increased the extraction efficiency and reduced the equilibrium time. Various parameters affecting the extraction efficiency were investigated, including the type and volume of extraction solvent and disperser solvent, extraction and ultrasonic time. Good linearity was obtained for NDPA in the range of 75-3000 ppb with the correlation coefficient (r2)≥0.9975. The LOD and LOQ of the method were 2.5 and 10 ppb respectively. The recoveries at three spiking levels ranged from 75.3 to 101.2% with the RSD less than 8.7% (n=3). This method offered a good alternative for routine analysis due to its simplicity and reliability.