in this research, the characteristics of cmp dioxane lignin (hardwood origin) and soda bagasse lignin (ethanol soluble fraction) and dioxane lignin of bagasse were studied using gel permeation chromatography, gas chromatography-mass spectrometry and 13c nmr spectroscopy and dfrc degradation procedure. the results indicated that the main structural units in lignins are phenyl propane skeletons b...

The review describes on-line derivatization/degradation methods employed in mass spectrometry to solve some structural and analytical problems. Advantages and applications of various positions of reaction systems connected mainly to a mass spectrometer or a gas chromatograph/mass spectrometer are considered. Among these are reaction systems connected directly to the mass spectrometer (reaction ...

To develop appropriate measures to prevent soil contamination in abandoned mining areas, an understanding of the spatial variation of the potentially toxic trace elements (PTEs) in the soil is necessary. For the purpose of effective soil sampling, this study uses hot spot analysis, which calculates a z-score based on the Getis-Ord Gi* statistic to identify a statistically significant hot spot s...

The determination of propoxyphene in oral fluid using solid-phase extraction and gas chromatography-mass spectrometry is described for the first time. The method employs collection of oral fluid with the Quantisal device, immunoassay screening of the specimen, confirmation of the positive screened samples after extraction using cation exchange/hydrophobic solid-phase extraction columns, optimiz...

The occurrence of tetrodotoxin (TTX) in sediment from Lake Suwa, Japan, was confirmed by a tissue culture assay, high-performance liquid chromatography, and gas chromatography-mass spectrometry. Altogether, 17 TTX-producing bacteria belonging to five genera were isolated from Lake Suwa and Pond Inokasira. Our results indicate that TTX and TTX-producing bacteria occur even in freshwater environm...

Disopyramide is determined in serum by gas chromatography with a nitrogen-selective detector, by liquid chromatography, and by gas chromatography--mass spectrometry. Comparable results are obtained with the three techniques, with a within-run and between-run precision of 5 to 10% (coefficient of variation). Least-squares analysis of data on patients' sera, analyzed first by gas chromatography (...

The anaerobic biodegradation of naphthalene (NAP) and phenanthrene (PHE) was investigated by using sediment collected from the Arthur Kill in New York/New Jersey harbor. The initial cultures were composed of 10% sediment and 90% mineral medium containing 20 mM sulfate. Complete loss of NAP and PHE (150 to 200 muM) was observed after 150 days of incubation. Upon refeeding, NAP and PHE were utili...

In this research, the characteristics of CMP dioxane lignin (hardwood origin) and soda bagasse lignin (ethanol soluble fraction) and dioxane lignin of bagasse were studied using gel permeation chromatography, gas chromatography-mass spectrometry and 13C NMR spectroscopy and DFRC degradation procedure. The results indicated that the main structural units in lignins are phenyl propane skeletons b...