Search results for "Barium hydroxide"

showing 4 items of 4 documents

Isocratic high-performance liquid chromatographic determination of tryptophan in infant formulas.

1996

The application to infant formulas of a method for tryptophan determination by isocratic HPLC with UV detection at 254 nm, after derivatization with phenyl isothiocyanate, was studied. Protein was hydrolysed by barium hydroxide at 120 degrees C for 8 h, followed by derivatization with phenyl isothiocyanate, HPLC and UV detection at 254 nm. The optimum chromatographic conditions (pH, ionic strength of elution solvent and eluent ratio) were established. The analytical parameters (linearity, precision, accuracy of derivatization and limits of detection and quantification) were determined. The values obtained demonstrated that the method is useful for determining the tryptophan content of infan…

AcetatesBiochemistryHigh-performance liquid chromatographySensitivity and SpecificityAnalytical ChemistryBarium hydroxidechemistry.chemical_compoundColumn chromatographyIsothiocyanatesHumansDerivatizationChromatography High Pressure LiquidAcetic AcidDetection limitChromatographyPhenyl isothiocyanateElutionOrganic ChemistryOsmolar ConcentrationTryptophanInfant NewbornTryptophanInfantGeneral MedicineHydrogen-Ion ConcentrationchemistrySolventsInfant FoodThiocyanatesJournal of chromatography. A
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Continuous hydrothermal synthesis of nanometric BaZrO3 in supercritical water

2007

Abstract Nanocrystalline barium zirconate (BaZrO 3 ) was synthesized using a hydrothermal synthesis process working in supercritical conditions and in a continuous way. By this method, we succeeded in the continuous and rapid production of nanopowders. As a preliminary work three barium precursors have been investigated: barium hydroxide (Ba(OH) 2 ), barium acetate (Ba(CH 3 COO) 2 ) and barium nitrate (Ba(NO 3 ) 2 ). Two of them (Ba(CH 3 COO) 2 and Ba(NO 3 ) 2 ) led to the pure perovskite phase. Then an experimental design has been conducted in order to determine the influence of the experimental parameters on the crystallinity and the grain size of the final product.

Materials scienceInorganic chemistrychemistry.chemical_element02 engineering and technology010402 general chemistry01 natural sciencesBarium hydroxideInorganic Chemistrychemistry.chemical_compoundCrystallinityMaterials ChemistryHydrothermal synthesisPhysical and Theoretical ChemistryComputingMilieux_MISCELLANEOUSPerovskite (structure)Barium acetateBarium[CHIM.MATE]Chemical Sciences/Material chemistryPowders-chemical preparation021001 nanoscience & nanotechnologyCondensed Matter PhysicsSupercritical fluidGrain size0104 chemical sciencesElectronic Optical and Magnetic MaterialsSupercritical water synthesischemistryChemical engineering[ CHIM.MATE ] Chemical Sciences/Material chemistryCeramics and CompositesBarium nitrate0210 nano-technologyBaZrO3
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ChemInform Abstract: Continuous Hydrothermal Synthesis of Nanometric BaZrO3in Supercritical Water.

2008

Abstract Nanocrystalline barium zirconate (BaZrO 3 ) was synthesized using a hydrothermal synthesis process working in supercritical conditions and in a continuous way. By this method, we succeeded in the continuous and rapid production of nanopowders. As a preliminary work three barium precursors have been investigated: barium hydroxide (Ba(OH) 2 ), barium acetate (Ba(CH 3 COO) 2 ) and barium nitrate (Ba(NO 3 ) 2 ). Two of them (Ba(CH 3 COO) 2 and Ba(NO 3 ) 2 ) led to the pure perovskite phase. Then an experimental design has been conducted in order to determine the influence of the experimental parameters on the crystallinity and the grain size of the final product.

chemistry.chemical_compoundCrystallinityBarium acetatechemistryChemical engineeringHydrothermal synthesischemistry.chemical_elementBarium nitrateBariumGeneral MedicineSupercritical fluidPerovskite (structure)Barium hydroxideChemInform
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Variability of pesticide mineralization in individual soil aggregates of millimeter size

2002

The aim of this study was to compare the 2,4-D mineralization in individual aggregates of millimeter size (3 size classes and 96 aggregates per size class). 14 CO 2 coming from the mineralization of 14 C ring-labeled 2,4-D and evolved by each aggregate incubated in microtiter plates was trapped with barium hydroxide on filters and measured using a Phosphorimager. We observed an important variability of mineralization in aggregates of each size class and in the different size classes of aggregates. The main factors responsible for these fluctuations could be a heterogeneous distribution of degrading microorganisms or of available carbon necessary for cometabolism.

[SDE] Environmental SciencesAggregate (composite)[SDV]Life Sciences [q-bio]Microorganismchemistry.chemical_elementCometabolismMineralization (soil science)Barium hydroxide[SDV] Life Sciences [q-bio]chemistry.chemical_compoundchemistryEnvironmental chemistry[SDE]Environmental Sciences24 DCarbon dioxideMicrobial biodegradationCarbon
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