The profile of high boiling point organic acids in urine samples from both normal subjects and patients suspected of having some form of metabolic disorder has been determined by combined gas chromatography-mass spectrometry. Fifteen different compounds eluting after hippuric acid have been identified, including two, cinnamoylglycine and acetyltributylcitrate, which have not been recognised pre...

organic acids exuded by plant roots increase solubility of soil micronutrient complexes. this study was carried out to evaluate adsorption isotherms of 4 acidic and 4 calcareous soils at presence of organic acids (citric, malic and oxalic acids). iron sorption and desorption isotherms are defined in to two systems including; system 1; soil-water-metal, system 2; soil-water-organic acid-metal). ...

It is known that the eating of most fruits leads to the formation of less acid urines due to the excess of base-forming elements in the fruits. The organic acids contained in the various fruits are oxidized within the body to carbon dioxide and water, so that the net result to the organism is a gain in base. However fruits such as cranberries, prunes, and plums, which contain benzoic acid or it...

After the urine was treated with urease, lyophilized, and trimethylsilylated, it was examined for metabolic profiles in Dalmatian dogs and Shetland sheepdogs by gas chromatography-mass spectrometry (GC/MS), which simultaneously analyzes organic acids, amino acids, sugars, sugar alcohols, purine and pyrimidine bases, and nucleosides. The profiles were compared with those from human specimens. As...

We used high-resolution glass capillary columns to study the trimethylsilyl derivatives of some acidic metabolites found in pooled urine specimens form control and postpartum subjects. About 30 compounds were identified by gas chromatography-mass spectrometry-computer techniques. In general, open tubular capillary columns effect better resolution of trimethylsilyl derivatives of organic acids t...

Fulvic acids from deep clay formations have been isolated by the International Humic Substances Society (IHSS) standard protocol and analyzed. Near edge X-ray absorption fine structure (NEXAFS) spectroscopy reveals, that the basic structural features relating to the origin of the clay organic matter (i.e., terrestrial or marine) are preserved even after the around 150 Ma since deposition (Juras...

We assessed the quantitative performances of a classical method for profiling urinary organic acids: ethyl acetate extraction/oxime-trimethylsilyl derivatization/GC-MS. Twenty-seven acids were quantified on the basis of specific ions in both scan and selected-ion monitoring modes. We found that the tuning of the mass detector severely affects the calibration factors, being critical to achieve q...