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Sample Preparation

Veterinary antibiotics have been released from fish and mussels by enzymes with the aid of an ultrasonic probe, which reduces the extraction time from several hours to just a few minutes, say Spanish researchers.

Solvent-enhanced headspace sorptive extraction, which aims to modify PDMS polarity using a solvent to increase its concentration capability, was applied to sample the volatile fractions of sage, thyme and roasted coffee.

Eggshell membranes are more effective adsorbents than octyl- or octadecyl silica particles for solid-phase extraction, say Chinese researchers, who used them to extract linear alkylbenzenesulphonates from river and tap water.

A multinational team of scientists has devised an efficient procedure for the extraction of a broad range of fluorochemicals in digested sewage sludge, based on ion pair extraction followed by SPE.

The liquid-liquid extraction dynamics of an ethyl ester of docosahexaenoic acid with silver ions were investigated using a kinetic model to predict the ester uptake using a slug flow prepared by a microchip.

Fat-soluble vitamins have been separated from a fruit juice-milk drink by magnetic SPE, using functionalised octadecylsilane particles modified with iron oxide, for subsequent analysis by capillary liquid chromatography.

A three-step protocol was developed for extracting four polybrominated diphenyl ethers from river and lake sediments for subsequent analysis by GC/MS. It gave detection limits which were at least as good as published techniques and provided cleaner chromatograms.

A cost effective, simple protocol for DNA extraction and visualization was devised, using buccal mucosal epithelia as a readily available source of cells which can be harvested in a painless, noninvasive manner, and seven criteria for evaluating the protocol

The recently developed electromembrane extraction process, which has been demonstrated for basic and acidic drugs, has been applied to the separation of peptides, in a systematic study by Scandinavian scientists.

A recently developed mixed-mode polymeric SPE sorbent containing weak anion exchange centres has been coupled online to HPLC to effect the automated extraction and determination of a group of acidic drugs from river water and sewage water.

The behavior of a drop of dichloromethane in water in contact with CO<sub>2</sub> at high pressure has been investigated with the purpose of analyzing the phenomena that take place during the supercritical fluid extraction of emulsions.

Ultrasonic cell grinder extraction has been used for the extraction of anthraquinones from a traditional Chinese herbal medicine, providing better yields than several other types of extraction.

The speed of detection of drugs banned by WADA can be increased by introducing the microwave-assisted extraction of suspect urine samples, say scientists in Italy. In some cases, sample preparation time is shortened by up to 90% compared with extraction by traditional mechanical shaking.

This theoretical work details the passive sampler response to possible environmental situations in which ambient concentrations vary linearly with time, decrease exponentially with time, constitute a pulsed event, or oscillate regularly with time.

An integrated flow-through system has been designed for the extraction, preconcentration and HPLC analysis of low levels of pyrethroid pesticides in soil, which will be useful when sample sizes are restricted.

Proteins have been digested in an online device that integrates buffer exchange, enrichment and enzymatic digestion to reduce the total processing time to about five minutes, enabling high-throughput analysis.

Two different procedures for the methylation of conjugated linoleic acid isomers were compared by silver ion-HPLC. A base catalysis/acid catalysis method gave different results from a base hydrolysis/methylation method.

A general technique has been developed for collecting samples from surfaces in the field, based on the desorption part of desorption electrospray ionisation. The spray of desorbed analytes is intercepted by a second surface for subsequent analysis by several techniques.

Cobalt has been extracted from environmental and biological samples by dispersive LLME, following complexation with a nitrosonaphthol in a highly selective procedure that gives almost 100% efficiency.

A new fiber based on titania-chitin sol-gel coated on a silver wire was developed for the headspace solid phase microextraction of aliphatic alcohols from apple juice samples.