Simultaneous Analysis Of Preservatives In Food And Cosmetics By High Performance Liquid Chromatography-mass Spectrometry

Determination of preservatives is an indispensable link in analysis of food or cosmetics teaching activity. Many scholars at home and abroad have developed the rapid, accurate and effective method on it actively. Because of the restriction to the development of instrument, the domestic scholars often use the chromatographic method on determination of preservatives. The kinds of preservatives detected simultaneously are limited. And so are the many methods in national standard. However, the foreign scholars initiated that determination of preservatives was further confirmed and even calculated by mass spectrometry.Because of the complex compositions in food or cosmetics, the analysis of them should generally be done after sample pretreatment. Sample pretreatment techniques have become important subjects in determination of preservatives in food and cosmeticsIn this work, two new and simple method of supercritical fluid extraction (SFE) and solid phase extraction (SPE) which are novel and more environmentally friendly sample preparation techniques combined with high performance liquid chromatography - mass spectrometry (HPLC-MS) were proposed for trace determination of preservations such as benzoic acid (BA), sorbic acid (SA), methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) in food and cosmetics.The studies in this thesis are included as follows:The application of HPLC-MS in food and cosmetics analysis was reviewed. The advance in HPLC-MS, SFE and SPE techniques and application of these techniques were also reviewed. The researches of preservations were discussed.Studies on the optimized analysis condition including the mobile phase, the gradient program conditions, the wavelength, the drying gas temperature, the positive or negative ion mode and its needle voltage, etc. were developed for preservatives by HPLC-MS.A rapid method for simultaneous separation and determination of methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) in cosmetics by HPLC-MS combined with SFE was developed. The recoveries (n=6) ranged from 95.15% to 107.69%. The relative standard deviations (n=6) were among 4.68～8.77%.A simple method for simultaneous separation and determination of methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) in food and cosmetics by HPLC-MS combined with SPE was developed. The recoveries (n=6) ranged from 95.00% to 109.35%. The relative standard deviations (n=6) were among 0.42—0.80%.A sensitive method for simultaneous separation and determination of benzoic acid (BA), sorbic acid (SA), methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) in food and cosmetics by HPLC-MS combined with SPE was developed. The recoveries (n=6) ranged from 95.48% to 110.34%. The relative standard deviations (n=6) were among 0.58～0.77%..The performance of SFE, coupled with HPLC-MS, was assessed for the determination of four parabens in cosmetics. Experimental parameters impacting the performance of SFE, such as extraction pressure, extraction temperature and extraction time were studied. The optimum extraction condition was performed with static extraction for 40 min by using carbon dioxide supercritical fluid at 14,000 kPa and 65℃. It was successfully applied to the determination of parabens in cosmetics without tedious pretreatment.The performance of SPE, coupled with HPLC-MS, was assessed for the determination of preservatives in food and cosmetics. Experimental parameters impacting the performance of SPE, such as filling materials, extraction solvent, time, stirring rate, sampling depth, etc. were studied. Overall, SPE proved to be a fast and simple tool for the determination of preservatives in salt samples.