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This work reports the method development for the simultaneous determination of methylmercury (MeHg+) and inorganic mercury (iHg) species in seafood. The study focused on the extraction and quantification of MeHg+ by liquid chromatography coupled to on-line UV irradiation and cold vapour atomic fluorescence spectroscopy (LC-UV-HG-AFS), using HCl 4 mol L-1 as extractant agent.

-GC-HRT analysis provides an effectual “molecular profile” of samples
-Confident compound identification through spectral similarity searches & robust formula determinations for fragment, molecular and adduct ions

The pyrolysis of asphaltenes from discrete crude oil samples shows distinct composition in terms of light and heavy aromatic hydrocarbons and alkyldibenzo-thiophenes. The use of Py–GC×GC–TOFMS is crucial for the determination of isomeric composition, and Py–GC–HRTOFMS with high resolution and high mass accuracy complements the identification by unequivocal chemical formula assignments. The study of the relationships of the crude oil and asphaltene composition are in progress.

A number of legacy contaminants and other pesticides, as well as a number of previously unknown compounds were tentatively identified in the pooled sample. Cl-H mass defect plots are a useful tool for filtering through complex data for the identification of halogenated contaminants. This technique functions as a screening tool for the identification of unknowns, and in the future, may be used as a form of fingerprinting to compare samples.

EI/CI workflow facilitates confident compound identification. Proper sample preparation is critical for the analysis of complex samples. GC-HRT provides high quality, accurate mass data for:
-Spectral similarity searches (NIST, Wiley, etc.)
-Formula determination (fragment, molecular, and adduct ions)

Analysis of detailed grab sample data from San Francisco Bay and Delta and development of regression relationships between EC, TDS and water quality constituents such as chloride, bromide, sodium, calcium, sulfate, alkalinity and hardness. The relationships in the interior Delta vary depending upon the percentage contributions from seawater, agricultural drainage and freshwater inflows.

This study was to analyze the total phenolics, beta-glucans, and beta-1,3-glucans in water extracts of three medicinal mushrooms (Ganoderma lucidum(GL), Inonotus obliquus(IO), and Phellinus linteus(PL)) under different extraction conditions.

A new dual-layer cartridge for the efficient extraction of PAHs from edible oils

Bisphenol A (BPA) is a primary monomer used in the manufacture of many plastics and epoxies. Some of these plastics are used as beverage containers and as liners and sealants for metal food containers. Because of BPA’s potential to act as an endocrine disrupter at low concentrations in humans, regulations have been enacted regarding BPA concentrations in food and beverages sold for human consumption.

In present work new preconcentration procedures combining microextraction techniques and X-ray fluorescence spectroscopy were developed. Proposed methodologies are promising tools for multielemental analysis enabling detection of natural pollutants in different water samples.