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Sample Preparation

Immunoglobulin G from cell cultures can be purified to 100% purity using a new separation protocol developed in Portugal. Aqueous two-stage extraction followed by two chromatographic steps was conducted without the need for conditioning steps between the separate operations.

Implementation of an uncomplicated SPE process for the rapid extraction and preconcentration of the alkaloids, colchicine, strychnine, aconitine, and nicotine, from water, apple juice, and nonfat milk samples is presented.

Two enrichment techniques aimed at a broad range of organic pollutants in water have been compared by researchers in Spain. Stir bar sorptive extraction and membrane-assisted solvent extraction both have their merits and gave comparable results for pollutants from estuarine water and seawater.

A three-phase liquid-liquid-liquid extraction incorporating an ionic liquid as the intermediate extractant has been used to enrich aromatic and aliphatic hydrocarbons in storm water. The technique is being used to help develop strategies for converting alternative water sources into drinking water.

An innovative process for the extraction of pure lycopene from tomato waste in water that uses the Naviglio extractor and water as extracting phase is presented. Lycopene was obtained in the <em>all-trans</em> form at a very high grade of purity

Two techniques for accelerated protein digestion have been demonstrated by a team of Chinese scientists who used infrared radiation for in-solution and in-gel proteolysis and an electric current for on-plate proteolysis. In all cases, the digestion times were reduced to 5 minutes but still gave good sequence coverage.

A range of organo-chlorine pesticides has been extracted successfully from aqueous samples by a form of liquid-phase microextraction in which the extracting droplet is frozen for easy recovery from the sample. Good enrichment factors were achieved and the subsequent GC detection limits were at the ppt level.

A simple and specific analytical method developed and tested for the determination of pharmaceuticals in mollusc samples involved a combination of microwave-assisted micellar extraction and solid-phase extraction using a non-ionic surfactant, polyoxyethylene 10 lauryl ether.

The conditions for optimal urine collection and storage for proteomics studies have been outlined by scientists in Denmark and the USA in an attempt to define standard protocols. The time of collection, storage temperature and number of freeze-thaw cycles were all found to influence the protein profile.

A new automated SPME system with an array of 96 fibres has been developed by the inventor of the technique to give a high throughput system. It was illustrated by the extraction of several drugs from whole blood with no sample pretreatment, showing excellent reproducibility and precision.

An effective sample preparation and presentation procedure for green tea infusions was developed to allow objective sensory analyses to be conducted and different infusions to be compared.

A four-probe microdialysis unit has been used to follow drug absorption in the different layers of the stomach and to sample ulcerated and healthy tissue within the same stomach simultaneously. The device provides a more accurate description of the distribution of drugs within the body.

A novel liquid-phase nanoscale extraction procedure developed by Taiwanese chemists uses the smallest volumes of sample and extraction solvent to date, yet provides sufficient analyte for detection by GC/MS. It also benefits from low cost and high speed.

An improved sample preparation procedure for the determination of 17 steroids, used potentially as growth promoters, in feed samples has been developed. The procedure is based on two reported LC-UV methods and includes a leaching process using acetonitrile, saponification, and SPE using polymeric cartridges.

The carbon and nitrogen isotopic signatures of avian blood are affected by the storage technique, with preservation in ethanol being particularly problematical. The bias that is introduced is of the same order as the changes caused by an underlying biological phenomenon, so could lead to misleading results.

Dispersive liquid-liquid microextraction of ionisable compounds has been rendered compatible with reversed-phase HPLC by combining it with in-syringe back extraction, say scientists from Taiwan. The new system was demonstrated with the removal of the drug clenbuterol from water.

The flexibility and simplicity of stir bar sorption extraction have been combined with the selectivity of molecularly imprinted polymers to produce a stir bar coated with Nylon-6 polymer imprinted with L-glutamine for the enantioseparation of this isomer.

The classic stir bar sorptive extraction method for enriching analytes in water has been extended into a sequential version to increase the recoveries of 80 pesticides. The first, conventional extraction with no added modifier is followed by a second extraction after the addition of salt, to optimise the recoveries of both hydrophobic and hydrophilic pollutants.

Peptides can be extracted from a wide range of tissues simply by soaking them in a solution of dihydroxybenzoic acid, say US researchers. The resulting extracts and the original tissue are stable for several years without freezing.

The state-of-the-art in sample preparation using SFE to monitor the content of polyhalogenated pollutants in aquaculture and marine environmental samples is reviewed, with reference to studies of biota and sediments published in the last 15 years.