Separation and purification of deoxynivalenol(DON) mycotoxin from wheat culture using a simple two-step silica gel column chromatography

Deoxynivalenol（DON） is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and in vitro. In this work, wheat culture was inoculated with a Fusarium graminearum PH-1 strain for DON production. The solvent system for crude extraction was acetonitrile-water（84：16, v/v）. A simple two-step silica gel column chromatography was employed to separate the DON mycotoxin from wheat culture, combined with preparative high performance liquid chromatography（preparative HPLC） to purify the compound. The solvent system for the second silica gel column chromatography was methylene chloride-methanol（17：1, v/v）, which provided a good elution effect selected on thin layer chromatography（TLC）. The target compound was identified by HPLC, and the chemical structure was confirmed by mass spectrometry（MS） and ~1H and ^（13）C nuclear magnetic resonance（NMR） spectroscopy. A total of 433 mg of purified DON was obtained from 1 kg of wheat culture, with a purity of 99.01%. The study had provided an easy-operating and cost-effective method to isolate an expensive compound in a simple way.

Separation of liquefied product of Salix psammophila by column chromatography and structure analysis of its components

The liquefied product of Salixpsammophila wood was separated by thin-layer chromatography （TLC） and column chromatography, and its structure was identified by nuclear magnetic resonance （NMR） spectra in our study. The separation result indicates that the sample of liquefied S. psammophila contained at least two categories of components. The structure of the main components was guaiacyl C-1, C-2 of the hydroxyphenyl propane, i.e., the aromatic nucleus protons of lignin. Degradation and polycondensation reactions occurred when the S. psammophila wood was liquefied in phenol. Polycondensation reactions occurred among the depolymerization products from cellulose, the aromatic depolymerization products from lignin and the products of the displacement reactions between phenoxide ion and cellulose.

Capillary Zone Electrophoretic Separation of Basic Proteins with Coated Columns Prepared by Sol-Gel Technology

Coated capillary columns were prepared by sol-gel technology and used in the separation of basic proteins with capillary zone electrophoresis. The results indicated that a significant decrease in protein adsorption was obtained and EOF was also diminished to zero in the pH range of 3-10.

Cyclonic separation process intensification oil removal based on microbubble flotation

The cyclonic-static microbubble flotation column has dual effects including the cyclonic separation and floatation separation with the characteristics of the small lower limit of the effective separation size, short separation time, large handling capacity, and low operation cost. It shows significant advantages in the oily wastewater treatment field, especially the polymer flooding oily wastewater treatment aspect. In this paper, the cyclonic separation function mechanism of the cyclonic-static microbubble flotation column was studied, the impact of the parameters including the feeding rate, aeration rate, circulating pressure, and underflow split ratio on the cyclonic separation efficiency was investigated, and the cyclonic separation efficiency model was established as well. In addition, by applying the Doppler Laser Velocimeter (LDV) and Fluent simulation software, the test and simulation to the single-phase flow velocity field of the cyclonic separation section of the cyclonic-static microbubble flotation column were carried out, and the velocity distribution rule of the cyclonic separation section was analyzed under the singlephase flow conditions.

Investigation on chiral capillary columns and their application in separation of enantiomers

Six chiral diamide stationary phases (CSPs), namely N-(3-carbobenzoxypropionyl)-L- Val-tert-butylamide (CSP-1), N-undecenoyl-L-Val-S-α-phenylethylamide (CSP-2), N-undecenoyl-L- Val-R-α-phenylethylamide (CSP-3), OV-225-L-Val-tert-butylamide (CSP-4), XE-60-L-Val-tert- butylamide (CSP-5) and polycyanoethyl vinyl siloxane-L-Val-tert-butylamide (CSP-6), were inves- tigated and CSP-6 was crosslinked within narrow bore (70 μm) fused silica capillary columns. The separation of amino acid enantiomers on this narrow bore column by gas chromatography (GC) is illustrated.

A fully electronic microfabricated gas chromatograph with complementary capacitive detectors for indoor pollutants

This paper reports a complete micro gas chromatography(μGC)system in which all the components are lithographically microfabricated and electronically interfaced.The components include a bi-directional Knudsen pump,a preconcentrator,separation columns and a pair of capacitive gas detectors;together,these form the iGC3.c2 system.All the fluidic components of the system are fabricated by a common three-mask lithographic process.The Knudsen pump is a thermomolecular pump that provides air flow to theμGC without any moving parts.The film heaters embedded in the separation columns permit temperature programming.The capacitive detectors provide complementary response patterns,enhancing vapor recognition and resolving coeluting peaks.With the components assembled on printed circuit boards,the system has a footprint of 8×10 cm^(2).Using room air as the carrier gas,the system is used to experimentally demonstrate the analysis of 19 chemicals with concentration levels on the order of parts per million(p.p.m.)and parts per billion(p.p.b.).The tested chemicals include alkanes,aromatic hydrocarbons,aldehydes,halogenated hydrocarbons and terpenes.This set of chemicals represents a variety of common indoor air pollutants,among which benzene,toluene and xylenes(BTX)are of particular interest.