For the analysis of residues of veterinary drugs, liquid chromatography (LC) is of increasing importance: some of these molecules are polar, heat-sensitive and/or difRcult to analyse by gas chromatography}mass spectrometry (GC-MS). Moreover, LC is the method of choice for components of high molecular mass. Since the introduction of benchtop LC-MS instruments, there has been an increasing number...

Although the estrogenic hormones 17 beta-estradiol and 17 alpha-ethinyl estradiol can be quantified in polluted waters by gas chromatography/mass spectrometry (GC/MS) and gas chromatography/tandem mass spectrometry (GC/MS/MS), the compounds often are present at concentrations below detection limits. Enzyme-linked immunosorbent assays (ELISAs) provide a sensitive and robust means of quantifying ...

This paper describes four recent applications of analytical pyrolysis in environmental science and engineering. In all applications, samples were analyzed in order to provide information about the origin of organic matter or changes to an organic matrix. In the first application, pyrolysis-gas chromatography/mass spectrometry (GC/MS) and pyrolysis-GC/flame ionization detection (FID) were used t...

The volatile composition of 20-year-old out-of-service creosote-treated railway wood sleepers was studied. The emitted volatile fraction was collected by means of dynamic purge-and-trap concentration at ambient temperature, and analyzed by comprehensive two-dimensional gas chromatography (GC x GC) hyphenated with mass spectrometric detection systems, using quadrupole (GC x GC/qMS) and time-of-f...

abstract: a combined gas chromatography-mass spectrometry (gc-ms) with headspace solid-phase micro extraction (spme) method has been employed for the analysis of the flavor volatiles of three different rice cultivar, including two modified iranian rice cultivars and hashemi rice cultivar during gelatinization. the proposed combination provided a powerful system for easy and rapid screening of a...

background & aim:jasmonic acid (ja) is regarded as endogenous regulators that play important roles in regulating stress responses, plant growth and development.effect of foliar application of ja on the essential oil and oil chemical components of hyssop (hyssopus officinalis l.) were investigated. experimental:  this study conducted in a crd with three replications and in experimental green...

background: urinary organic acids are water-soluble intermediates and end products of the metabolism of amino acids, carbohydrates, lipids, and a number of other metabolic processes. in the hereditary diseases known as organic acidurias, an enzyme or co-factor defect in a metabolic pathway leads to the accumulation and increased excretion of one or more of these acidic metabolites. gas chromato...

Natural remedies, such as those based on traditional Chinese medicines, have become more popular also in western countries over the last 10 years. The composition of these herbal products is largely unknown and difficult to determine. Moreover, since plants respond to their environment changing the metabolome, the composition of plant material can vary depending on the plant growth conditions. ...

Two techniques based on analytical pyrolysis and mass spectrometry, direct exposure-MS (DE-MS) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), were used to characterise waterlogged archaeological wood and to study degradation patterns of wood in aqueous environments. The two techniques were applied to samples from the excavation of the Site of the Ancient Ships of Pisa San Rossor...

Phytochemical screening and gas chromatography-mass spectrometry (GC-MS) methods were used to determine the phytochemical components of various extracts stems roots Catharanthus roseus. Preliminary n-hexane, chloroform, ethyl acetate methanol roseus carried out identify class compounds present in each extract. The results exhibited that steroids, terpenoids, flavonoids phenolic found every extr...