Characterization Of Nonionic Surfactant By Supercritical Fluid Chromatography Combined With Mass Spectrometry

With the development of nonionic surfactant,it is widely used in the food,personal care,and pharmaceutical industries.In fact,the products of nonionic surfactant are complex mixtures of oligomers and the quality of products is irregularity.Different quality products have a great influence on their application.So,it was necessary to develop an effective method to characterize the ingredients of nonionic surfactant,which can also help to optimize processing technique of production and improve the quality of products.In this work,the three main contents are as follow:1?A method was developed to characterize the polysorbate 80 by supercritical fluid chromatography combined with mass spectrometry(SFC-MS)without pre-treatment.Some crucial parameters,such as temperature,back pressure and flow rate were optimized.SFC could distin-guish n-mer from(n-1)-mer and(n+1)-mer in the same series,which provided the high separation resolution needed for quantitative determination of each oligomer in same series.Furthermore,the characteristic ion fragments were found in MS/MS experiment and used to identify different series.The results revealed that main components of this nonionic surfactant comprise PEO,PEO-oleates,PEO-isosorbide,PEO-isosorbide oleates(s),PEO-sorbitan,PEO-sorbitan oleate(s)etc.The relationship between molecular structure of these oligomers and chromatographic retention behavior in SFC were also investigated2?A method was developed to characterize the polysorbate 80 by SFC-MS,the fragmentation mechanism from the different adduct ions in MS/MS experiment were investigated.It was found that sodiated stearate ion can undergo charge-remote 1,5-H rearrangement over the ester group.The oligomers of 8 series were identified.The developed SFC-MS method was compared to the UHPLC-MS method.The orthogonality of oligomers separation by these two methods was demonstrated.3?The SFC-MS and UHPLC-MS were used to characterize a complex pentaerythritol fatty acid ester.The loss of neutral fatty acid molecule was observed in MS/MS experiment,which could used to identify the composition of fatty acid easters.The hydrogen atom rearrangement reaction was used to interpret the formation of characteristic ions from sodiated ions.In both SFC and UHPLC,the retention behaviour of pentaerythritol fatty acid tetraester is similar.The result showed that UHPLC is more suitable for the separation due to weak polarity of pentaerythritol fatty acid tetraester.