[Separation and identification of Fischer-Tropsch wax by high temperature gas chromatography-mass spectrometry].

Fischer-Tropsch (FT) wax is an important material produced from FT synthesis reactions. In this study, an improved separation and identification method for FT wax by high temperature gas chromatography (HTGC) coupled with cold-on-column (without pretreatment) was developed. In our improved separation procedure, the carrier gas was changed to helium and a long chromatographic column was adapted for use at high temperature. The n-alkanes in FT wax were well separated from other unknown components and the heavy components with carbon numbers higher than C90 could be eluted. Unknown components of the FT wax fraction were confirmed as alkanes, alkenes and oxygenated compounds by using HTGC-mass spectrometry. These results improve our understanding of the FT synthesis process and increase our detailed knowledge of FT products.

[Preparation and adsorption characteristics of surface-imprinted polymer using bovine serum albumin and lysozyme as double template proteins].

The double template surface-imprinted polymer (Bi-MIP)) was synthesized by atom transfer radical polymerization (ATRP) in aqueous media, using bovine serum albumin (BSA) and lysozyme (Lyz) as the template prteis, X-isopropylacrylamide (NIPAAm) and acrylamide (AAm) as the monomers and X-3-(dimethylamino) propyl-methacrylamide (DMAPMA) as the assistant of basic functional monomner. The ATHP possessed the mild reaction conditions and can be initiated at room temperature without heating and ultraviolet radiations. The preparation conditions of imprinted polymer were optimized, and the content of DMAPMA as the assistant of basic functional monomer was investigated. The results showed that Bi-MIP exhibited the good adsorption capacity and selectivity in single protein solution and in mixed protein solution when the volume of DMAPMA in the preparation process of Bi-MIP was 20 µL. The rebinding capacity of Bi-MIP was evaluated according to adsorption isotherm of the imprinted polymer. The Langmir adsorption model was employed to describe the isotherms and revealed that Bi-MIP exhibited the maximum rebinding to 13SA and Lyz at 10.2 mg g and 19.2 mg/g, respectively. And Bi-MIP had good imprinting effect and adsorption capacity to templates BSA and Lyz from egg white and bovine serum samples. This will provide a new way for specific recognition of the double multiple target proteins in the complex biological samples.

[Determination of low-carbon alcohols, aldehydes and ketones in aqueous products of Fischer-Tropsch synthesis by gas chromatography].

A method for the determination of low-carbon (C1-C8) alcohols, aldehydes and ketones in aqueous products of Fischer-Tropsch synthesis was developed by gas chromatography. It included the optimization of separation conditions, the precision and accuracy of determination, and the use of correction factors of the analytes to ethanol for quantification. The aqueous products showed that the correlation coefficients for ethanol in different content ranges were above 0.99, which means it had good linear correlations. The spiked recoveries in the aqueous samples of Fischer-Tropsch synthesis were from 93.4% to 109.6%. The accuracy of the method can satisfy the requirement for the analysis of the aqueous samples of Fischer-Tropsch synthesis. The results showed that the total mass fractions of the major low-carbon alcohols, aldehydes, ketones in aqueous products of Fischer-Tropsch synthesis were about 3%-12%, and the contents of ethanol were the highest (about 1.7%-7.3%). The largest share of the total proportion was n-alcohols, followed by isomeric alcohols, aldehydes and ketones were the lowest. This method is simple, fast, and has great significance for the analysis of important components in aqueous products of Fischer-Tropsch synthesis.

Ionic liquid-assisted SDS-PAGE to improve human serum protein separation.

Ionic liquid (IL)-assisted sodium dodecyl sulfate polyacrylamide gel electrophoresis (ILs-SDS-PAGE) was presented to improve protein separation. ILs were employed during the preparation process of polyacrylamide gel, then the modified gel was used for commercial protein marker, binary bovine serum albumin/lysozyme (BSA/Lyz) and human serum separation. The influence of ionic liquid concentration, cation alkyl chain length, cation and anion types on proteins separation were investigated. The results showed that ILs played a role in improving some protein separation, and ILs-SDS-PAGE provided higher resolution and separation efficiency than ordinary SDS-PAGE for low and middle relative molecular mass proteins in human serum. In addition, the principle of ILs-SDS-PAGE was discussed and the comparison of ILs-SDS-PAGE with ordinary SDS-PAGE and Native PAGE was made.

Integration of carboxyl modified magnetic particles and aqueous two-phase extraction for selective separation of proteins.

Both of the magnetic particle adsorption and aqueous two-phase extraction (ATPE) were simple, fast and low-cost method for protein separation. Selective proteins adsorption by carboxyl modified magnetic particles was investigated according to protein isoelectric point, solution pH and ionic strength. Aqueous two-phase system of PEG/sulphate exhibited selective separation and extraction for proteins before and after magnetic adsorption. The two combination ways, magnetic adsorption followed by ATPE and ATPE followed by magnetic adsorption, for the separation of proteins mixture of lysozyme, bovine serum albumin, trypsin, cytochrome C and myloglobin were discussed and compared. The way of magnetic adsorption followed by ATPE was also applied to human serum separation.

The preparation of bovine serum albumin surface-imprinted superparamagnetic polymer with the assistance of basic functional monomer and its application for protein separation.

Currently, small proteins imprinting are more reported since large proteins molecular imprinting faces challenge due to their bulk size and complex structure. In this work, bovine serum albumin (BSA) surface-imprinted magnetic polymer was successfully synthesized based on atomic transfer radical polymerization (ATRP) method in the presence of common monomer (N-isopropylacrylamide) with the assistant of basic functional monomer (N-[3-(dimethylamino)propyl]-methacrylamide), which provides a achievable attempt for imprinting larger target proteins based on the ATPR with the mild reaction conditions. The BSA-imprinted polymer exhibited higher adsorption capacity and selectivity to BSA over the non-imprinted polymer. Competitive adsorption tests indicated the BSA-imprinted polymer had better selective adsorption and recognition properties to BSA in the mixture. The obtained BSA-imprinted polymer was applied to bovine serum, which also showed selectivity to BSA. In addition, a conventional aqueous two-phase solution of PEG/sulphate was used as elution for adsorbed BSA, which was compared with common NaCl elution.

Superparamagnetic lysozyme surface-imprinted polymer prepared by atom transfer radical polymerization and its application for protein separation.

Molecular imprinting as a promising and facile separation technique has received much attention because of their high selectivity for target molecules. In this study, the superparamagnetic lysozyme surface-imprinted polymer was prepared by a novel fabricating protocol, the grafting of the imprinted polymer on magnetic particles in aqueous media was done by atom transfer radical polymerization (ATRP), and the properties of the imprinted polymer were characterized in detail. Its high selective adsorption and recognition to lysozyme demonstrated the separation ability of the magnetic imprinted material to template molecule, and it has been used for quick and direct separation of lysozyme from the mixture of standard proteins and real egg white samples under an external magnetic field. Furthermore, the elution of lysozyme from the imprinted material was achieved by PEG/sulphate aqueous two-phase system, which caused lysozyme not only desorption from the imprinted materials but also redistribution in the top and bottom phase of aqueous two-phase system. The aqueous two-phase system exhibited some of the extraction and enrichment effect to desorbed lysozyme. Our results showed that ATRP is a promising method for the protein molecularly imprinted polymer preparation.