Research On Analysis Of N-nitrosamines In Cosmetics Using Gas Chromatography-Tanden Mass Spectrometry

Cosmetics are substances or products applied to any part of the body surface(skin,hair,nails,lips,etc.)by smearing,sprinkling,spraying or other similar methods for cleansing,beautifying,promoting attractiveness,or altering the appearance without affecting the body’s structure or functions.In recent years,China’s cosmetics industry is developing rapidly.Cosmetics have become a new hot spot of consumption and they have become important consumer goods in people’s daily life,meanwhile their safety has attracted more and more attention of consumers.N-nitrosamines have been proved to have acute toxicity,carcinogenicity,teratogenicity,mutagenicity,and pose a great threat to human health.As cosmetics will stay on the surface of human skin for a long period,the toxic and harmful substances of cosmetics may enter the body through the skin surface,thus threaten the health of consumers,so it is of great significance to establish a method for the detection of N-nitrosamines in cosmetics.In this paper,thirteen kinds of N-nitrosamines(N-nitrosodimethylamine,N-nitrosomethylethylamine,N-nitrosodiethylamine,N-nitrosopyrrolidine,N-nitrosodi-n-propylamine,Nmethyl-N-nitrosoaniline,N-nitrosomorpholine,N-Nitrosopiperidine,N-nitroso-N-ethylaniline,N-nitrosodi-N-butylamine,N-nitrosodiphenylamine,N-nitrosodicyclohexylamine,N-nitrosodibenzylamine)were selected as the research object.The analytics in water-soluble(emollient water,facial mask,facial cleanser,shampoo,etc.)and fat-soluble(plant essence emulsion,massage cream,hairspray,lip rouge,plant essence powder,eyelids,etc.)cosmetics were determined by the method with high sensitivity and selectivity of gas chromatography– tandem mass spectrometry(GC-MS/MS).Methodological studies results showed that this method was performed in the analysis of the analytes in their respective linear ranges with good correlation coefficients,high sensitivity and high selectivity,and is suitable for the rapid detection of 13 N-nitrosamines in cosmetics.The specific research contents and results of this study were as follows:Firstly,a 13 N-nitrosamines mixed standard solution was concocted with dichloromethane.The conditions for gas chromatography and mass spectrometry were optimized.CP-Sil 8 CB column(30 m×0.25 mm×0.50 μm)was used;temperature programming started at 50 ℃,holding for 1.0 min,and then increasing to 200 ℃ at a rate of 10 ℃/min;increasing to 280 ℃ at a rate of 40 ℃/min,holding for 4.0 min,and increasing to 320 ℃ at a rate of 40 ℃ /min,maintaining at 320 ℃ for 3 min,injection port temperature: 250 ℃,inject volume,2 μL,injection mode: split,split ratio: 10 : 1;carrier gas: nitrogen,purity≥99.999%;column flow: 1.0 mL/min,Ionization model: EI,electron energy: 70 eV;ion source temperature: 230 ℃,Quadrupole temperature: 280 ℃,solvent delay: 4 min;multiple reaction monitoring mode(MRM);subsection type scanning: 3-8 min: NDMA,NEMA,NDEA;8-12 min: NPYR,NDPA,NMPhA,NMOR,NPIP,NEPhA;12-16 min: NDPhA;16-29 min: NDPhA,NDChA,NDBzA.Secondly,a method for the simultaneous determination of 13 N-nitrosamines in water-soluble cosmetics(emollient water,facial mask,facial cleanser,shampoo,etc.)by GC-MS/MS was established.The conditions of extraction and QuEChERS method were optimized.The result showed that sample of water-solubile cosmetics was dispersed by adding water,and followed by acetone,the samples were purified by QuEChERS,directly injectied into chromatographic column for detection.In the optimized conditions,the results demonstrated that the average recoveries of 13 N-nitrosamines at three different spiked levels ranged from 76.2%-98.9%.With the relative standard deviation(RSDs)of 0.3%-9.4%.The limit of detections(LODs)were 0.20-1.50 mg/kg.This method is simple,and efficient,and is suitable for the rapid detection of 13 N-nitrosamines in water-solubility cosmetics.Based on the research of water-soluble cosmetics,combine freezing lipid filtration with QuEChERS,rapid detection method of 13 N-nitrosamines in fat-soluble cosmetics(Plant essence emulsion,Massage Cream,Hairspray,Lip rouge,Plant essence powder,Eyelids,etc.).The pretreatment method can remove most of the fat,sterol and paraffin in cosmetics,the purified sample solution is more clean and little interference.the results demonstrated that the average recoveries of 13 N-nitrosamines ranged from 68.3%-98.6%,RSDs was 0.4%-9.7% at three different spiked level.The limit of detection(LOD)were 0.20-1.50 mg/kg,respectively.This method is simple,efficient,reliable,accurate,and is suitable for fast detection of 13 N-nitrosamines in fat-soluble cosmetics.