Here we provide the geochemical dataset that our research group has collected after 10 years of investigation in the Sierra Nevada National Park in southern Spain. These data come from Holocene sedimentary records from four alpine sites (ranging from ∼2500 to ∼3000 masl): two peatlands and two shallow lakes. Different kinds of organic and inorganic analyses have been conducted. The organic matt...

Gas chromatography-mass spectrometry (GC-MS) is a rapid method that provides rich information on isotopomer distributions for metabolic flux analysis. First, we established a fast and reliable experimental protocol for GC-MS analysis of amino acids from total biomass hydrolyzates, and common experimental pitfalls are discussed. Second, a suitable interface for the use of mass isotopomer data is...

The aim of this article was the gas chromatography–mass spectrometry (GC-MS) analysis oforganic matter from a residual liquor sample (S.C. Alum S.A., Tulcea), extracted by solid-phasemicroextraction method (SPMA) and derivatized with N-(tert-butyldimethylsilyl)-Nmethyltrifluoroacetamide(MTBSTFA) as silylating agent. [...]

A method for the measurement of uric acid in human serum by isotope dilution-mass spectrometry is described. The analytical procedure consists of the following steps: Addition of [1,3-15N2]uric acid to the serum sample; ion exchange chromatography on AG1-X2; formation of the trimethylsilyl derivative; gas liquid chromatography-mass spectrometry (GC-MS), selected ion monitoring (SIM) at m/z-valu...

results based on the results obtained by the applied technique, the presence of carcinogenic compounds, n-nitrosomethyl-vinylamine (162 µg/g), n-nitrosonornicotine (6.3 µg/g), and acetaldehyde (117 µg/g) was confirmed in the sample. objectives the current study aimed to chemically analyze, separate and measure the existing substances in a type of chewing tobacco. materials and methods in the cu...

Physical and chemical properties that may be used to determine the purity of several Fusarium mycotoxins have been investigated. A combination of analytical procedures, which include high performance thin-layer chromatography (HPTLC), liquid chromatography (LC), gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), ultraviolet spectrometry (UV), and nuclear magnetic resonance (...

The aroma-active compounds in Jinhua ham processed and stored for 9, 12, 15 and 18 months were extracted by dynamic headspace sampling (DHS) and solvent-assisted flavor evaporation (SAFE) and analyzed by gas chromatography-olfactometry-mass spectrometry (GC-O-MS). In GC-O-MS, volatile compounds were identified based on their mass spectrum, linear retention index (LRI), odor properties, or refer...

The determination of γ-nonalactone as one of the important odor-active compounds in freshly cooked non-scented rice is reported. It was evaluated by gas chromatography-olfactometry (GC-O) analysis and identified by gas chromatography-mass spectrometry (GC-MS) analysis in the headspace above the freshly cooked non-scented rice samples extracted by using a modified headspace solid-phase microextr...

Multiple field studies have suggested chemistry within a forest canopy is poorly understood due to inadequate detection and quantification of reactive biogenic emissions, such as terpenes. To measure emission rates of terpenes at Blodgett Forest, a coniferous forest in the Sierra Nevada mountains of California, we placed enclosures over branches of the dominant species at the site – Ponderosa p...

to assess the sources, entry routes and degree of contamination of pah compounds in surface sediments of the southwestern caspian sea coasts (gillan province) total of 129 surface sediment samples from 28 rivers and 5 transect across the gillan province coasts (from astara to lahijan; 10, 20 and 50 m depth) were collected in the spring and summer of 2012. after extraction using soxhlet method, ...