Isolation of lipids from photosystem I complex and its characterization with high performance liquid chromatography/electrospray ionization mass spectrometry.

A method for simultaneous analysis of lipids extracted from photosystem I complex was developed with high performance liquid chromatography/electrospray ionization mass spectrometry. The photosystem I complex was firstly solubilized and separated using deoxycholate polyacrylamide gel electrophoresis method after ultrasonic treatment of the sample (leaves of pea, Pisum sativum L.).

Enantioseparation of 2-O-beta-D-glucopyranosyl-2H-1,4-benzoxazin-3(4H)-one and its 7-chloro-derivative by capillary zone electrophoresis using native and substituted beta-cyclodextrins as chiral additives.

Efficient, rapid and inexpensive methods were established for the chiral separation of two glucopyranosyl compounds from plant extracts, by capillary zone electrophoresis (CZE). Baseline separation was achieved for both compounds. Several native cyclodextrins and their derivatives were tried as chiral selectors.

Analysis and determination of biological activity of short-chain peptides from porcine brain hydrolysate.

Gel permeation chromatography fractions of short-chain peptides from a hydrolysate product, which in turn was from the purified porcine brain through enzyme hydrolysis, were tested for their biological activities. The results showed that the fractions A4 and A5 had significant biological activities. The two fractions were analyzed with analytical techniques such as high-performance liquid chromatography (HPLC), capillary zone electrophoresis (CZE), isoelectric focusing (IEF), discontinuous sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).

Exact electric field strength over the packed capillary electrochromatography column bed, theoretical considerations and practical determination.

On the basis of the experiments, it was proved that Ohm's law holds true in a capillary electrochromatography (CEC) column. By using the additivity of the potential drop over the packed and unpacked sections, the exact values of the electric field strength over the packed CEC column bed were determined experimentally. The ratio of the resistance of packed CEC column sections to that of an open capillary of the same length (Rp/Ro,Lp) were calculated.

Comparative study of the composition of TCM Radix notoginseng extract samples before and after acetylation with UV and ELSD detection.

Objective: To study the derivation, acetylation specifically, as well as the application of evaporative light-scattering detector (ELSD) detection of Panax notoginseng extract for a better understanding of its components, as well as to study the authentication of this Traditional Chinese Medicine (TCM).

Methods: Acetonitrile-water gradient elution of the samples was used for the analysis and the ultraviolet (UV) detection used to observe the difference between the extract samples before and after acetylation. Mobile phases containing 30% and 85% acetonitrile, respectively, were used to observe the differences between chromatograms of the samples obtained using UV and ELSD detection.

Electrochromatographic properties of synthetic poly(styrene-divinylbenzene) encapsulated packing material and sulphonic cation-exchange phase based on the former.

Objective: To develop new kinds of stationary phases suitable for applications in capillary electrochromatography (CEC), as well as in LC, which can be tailored to realize selective separations of solutes difficult to separate with conventional stationary phases.

Methods: Purchased spherical silica particles (5 microm) were refluxed in anhydrous toluene with vinyl-triethoxysilane for 18 h, to modify the surface with vinylsilyl groups. The silylated silica particles were subsequently stirred in an n-henanol-acetonitril mixture (1:4, volume fraction) for 18 h.

Chromatographic behavior of packing materials for capillary electrochromatography with a coating of different immobilized polysiloxanes.

Octadecyl silyl silica (ODS) phase coated with immobilized polysiloxanes (OV1701, SE-54, SE-30) were synthesized, their characteristics as capillary electrochromatography (CEC) column packing materials were studied. It was found that, although the polysiloxane coatings were different in polarity, the resulting packing materials showed the highest efficiencies when the respective coating ratios (polysiloxane:ODS, w/w) were all 20-30%. As expected, packing materials coated with different polysiloxanes resulted in different selectivity on solute pairs.