微生物学技术

The method for the determination of multiclass pesticides in water samples by headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) is described. Of the 174 pesticides, 158 are extracted with a polyacrylate-coated fiber at 30 to 100�C and a ...

We have developed a method using in-tube solid-phase microextraction coupled with liquid chromatography-mass spectrometry (SPME-LC-MS) for the assay of herbicides in water samples. Chlorinated phenoxy acid herbicides have been automatically extracted into a DB-WAX capilla ...

Ion pair admicelle-based solid-phase extraction (SPE) is proved here to be a valuable strategy to concentrate quaternary ammonium compounds (quats; chlormequat, mepiquat, paraquat, diquat, and difenzoquat) from drinking water. The approach is based on the adsolubilization of qua ...

This chapter demonstrates the versatility and feasibility of coupled-column reversedphase liquid chromatography (LC/LC) for the rapid, selective, and sensitive determination of pesticides in environmental water samples. The work includes the setup and application of three ...

Solid-phase extraction (SPE) represents a suitable way to clean up and preconcentrate samples containing traces of chlorinated phenoxyacids. High selectivity levels may be obtained using columns packed with materials based on well-defined molecular recognition mechanism ...

An automated system appropriate for the analysis of a variety of chemical classes of pesticides and conversion products in water is presented. The system is based on the online solid-phase extraction (SPE) of target solutes followed by high-performance liquid chromatography (HPLC) ta ...

2-Alkyl-4-quinolones (AQs) such as 2-heptyl-3-hydroxy-4-quinolone (PQS) and 2-heptyl-4-quinolone (HHQ) are quorum sensing signal molecules. Here we describe two methods for AQ detection and quantification that employ thin layer chromatography (TLC) and microtitre plate assa ...

In most bacteria, a global level of regulation exists involving intercellular communication via the production and response to cell density-dependent signal molecules. This cell density-dependent regulation has been termed quorum sensing (QS). QS is a global regulator, which has b ...

At least 29 triazines and 36 degradation products have been reported in the literature. For many reasons, no single method enables the simultaneous extraction and analysis of all of these compounds. Three methods are described for monitoring triazines and degradation products in filte ...

The river analyzer (RIANA) is an optical immunosensor able to determine different types of organic pollutants in water samples. Interaction between fluorescently labeled antibody and analyte takes place on a solid-liquid interface and is detected by measuring the fluorescence. The ...

Vibrios are Gram-negative γ-proteobacteria that are ubiquitous in marine, estuarine, and fresh-water environments and encompass a diverse group of bacteria, including many facultative symbiotic and pathogenic strains. Toxigenic Vibrio cholerae strains belonging to the se ...

Aeromonas species are water-borne bacteria that are often found as environmental and food contaminants. They have been involved in human diarrhea disease and extraintestinal infections and are considered as emerging pathogens. These infections are probably acquired by food and w ...

This chapter describes a high-pressure liquid chromatography (HPLC) method for measuring aflatoxin B1 and its metabolites isolated from rat hepatocytes. AFB1, AFQ1, AFM1, and AFP1 concentrations are determined using reverse-phase HPLC. The isocratic mobile phase is 18% dimethyl ...

Bacillus cereus causes two types of food poisoning, emetic and diarrheal. The emetic disease is caused by a small cyclic polypeptide (cereulide), and the diarrheal disease is caused by three different enterotoxins. Commercially available kits are used for detection of two of the enteroto ...

Clostridium botulinum is a diverse group of anaerobic spore-forming organisms that produce lethal botulinum neurotoxins (BoNT) during their growth. BoNTs cause a paralytic condition, botulism, to man and animals. The most common forms of human botulism include the classical foodbo ...

Globally Campylobacter has been recognized as a leading cause of human gastroenteritis, generating considerable interest in the development of special selective techniques for optimal growth, isolation, and preservation of Campylobacter from clinical and environmental ...

The “O157:H7 complex” is comprised mostly of enterohemorrhagic Escherichia coli (EHEC) strains, with serotype O157:H7 being the prototypic and predominate pathogenic strain in the complex. However, several phenotypic O157:H7 variants and genetically closely related O55:H7 s ...

Subtyping Listeria monocytogenes by macrorestriction and pulsed-field gel electrophoresis (PFGE) provides sensitive and epidemiologically relevant discrimination between strains and allows public health officials to detect potential common source outbreaks of l ...

Plesiomonas shigelloides is a micro-organism involved in gastroenteritis infections and food poisoning. Because there is a lack of specific and sensitive methods of detection and identification of this bacterium in clinical diagnostic laboratories, the pathogen has usually b ...

Salmonella are one of the most widespread micro-organisms found in the global food chain; they are frequently isolated from raw meats, poultry, and milk. They are responsible for a number of clinical syndromes, including gastroenteritis. Pulsed-field gel electrophoresis (PFGE) has be ...