Determination of pterins in urine by HPLC with UV and fluorescent detection using different types of chromatographic stationary phases (HILIC, RP C8, RP C18)

The purpose of this study was to characterize some types of biomass wastes resulted from different activities such as: agriculture, forestry and food industry using thermogravimetric and ICP-MS analyses. Also, it was optimized an ICP-MS method for the determination of As, Cd and Pb from biomass ash samples. The ICP-MS analysis revealed that the highest concentration of metals (As, Cd, Pb) was recorded in the wood waste ash sample, also the thermogravimetric analysis indicated that the highest amount of ash was obtained for the same sample (26.82%). The biomass wastes mentioned in this study are alternative recyclable materials, reusable as pellets and briquettes. Keywords: ash, biomass, ICP-MS, minor elements, TG

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Studies on the Behavior Some Paints in Electro-insulating Fluid Based on Vegetable Esters

Revista de Chimie ◽

10.37358/rc.18.5.6276 ◽

2018 ◽

Vol 69 (5) ◽

pp. 1139-1144

Author(s):

Iosif Lingvay ◽

Adriana Mariana Bors ◽

Livia Carmen Ungureanu ◽

Valerica Stanoi ◽

Traian Rus

Keyword(s):

Structural Changes ◽

Oxidation Processes ◽

High Oleic ◽

Painting Materials ◽

Insulating Paper ◽

Different Types ◽

Mechanism And Kinetics ◽

Kinetics Of ◽

Natural Ester

For the purpose of using three different types of painting materials for the inner protection of the transformer vats, their behavior was studied under actual conditions of operation in the transformer (thermal stress in electro-insulating fluid based on the natural ester in contact with copper for electro-technical use and electro-insulating paper). By comparing determination of the content in furans products (HPLC technique) and gases formed (by gas-chromatography) in the electro-insulating fluid (natural ester with high oleic content) thermally aged at 130 �C to 1000 hours in closed glass vessels, it have been found that the presence the investigated painting materials lead to a change in the mechanism and kinetics of the thermo-oxidation processes. These changes are supported by oxygen dissolved in oil, what leads to decrease both to gases formation CO2, CO, H2, CH4, C2H4 and C2H6) and furans products (5-HMF, 2-FOL, 2 -FAL and 2-ACF). The painting materials investigated during the heat treatment applied did not suffer any remarkable structural changes affecting their functionality in the electro-insulating fluid based on vegetable esters.

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Gas-Liquid Chromatographic Determination of Technical Chlordane Residues in Food Crops: Interpretation of Analytical Data

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/58.5.1051 ◽

1975 ◽

Vol 58 (5) ◽

pp. 1051-1061

Author(s):

William P Cochrane ◽

James F Lawrence ◽

Young W Lee ◽

Ronald B Maybury ◽

Brian P Wilson

Keyword(s):

Field Experiments ◽

Stationary Phases ◽

Analytical Data ◽

Chromatographic Determination ◽

Electron Capture Detection ◽

Food Crops ◽

Liquid Chromatographic Determination ◽

Consistent Method ◽

Liquid Chromatographic

Abstract An interlaboratory investigation of technical chlordane residues in food crops was carried out to determine the most practical and consistent method of reporting results. Using a technical chlordane reference standard, 8 gas chromatographic stationary phases were studied for their resolution capabilities. The best separations were obtained with SE-30 and its OV-1 equivalent. Using these columns and electron capture detection, potatoes and carrots from supervised field experiments were analyzed in duplicate and quantitated by using 4 methods of calculation. The data were statistically treated to determine the precision and bias for each method. Also, 1 sample was analyzed in duplicate on 2 different occasions by 6 laboratories to substantiate the initial conclusions. Based on the criterion of high precision it is suggested that a comparison of total area under the chromatogram of the sample with total area of a standard technical chlordane be the method of quantitation. Only peaks which are common to both standard and sample have any significance in this type of calculation.

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Determination of sterols by capillary column gas chromatography. Differentiation among different types of olive oil: Virgin, refined, and solvent-extracted

Journal of the American Oil Chemists Society ◽

10.1007/bf02517973 ◽

1996 ◽

Vol 73 (12) ◽

pp. 1685-1689 ◽

Cited By ~ 39

Author(s):

Oroncio Jiménez de Blas ◽

Amando del Valle González

Keyword(s):

Gas Chromatography ◽

Olive Oil ◽

Capillary Column ◽

Different Types ◽

Capillary Column Gas Chromatography

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Innovative TLC-densitometric method with fluorescent detection for simultaneous determination of ternary anti-diabetic mixture in pharmaceutical formulations and human plasma

Microchemical Journal ◽

10.1016/j.microc.2021.106131 ◽

2021 ◽

pp. 106131

Author(s):

Noha S. Abbas ◽

Sayed M. Derayea ◽

Mahmoud A. Omar ◽

Gamal A. Saleh

Keyword(s):

Simultaneous Determination ◽

Human Plasma ◽

Pharmaceutical Formulations ◽

Fluorescent Detection

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The Importance of Diet in Predicting the Remission of Urticaria—Determination of Allergen-Specific IgE

Medicina ◽

10.3390/medicina57070679 ◽

2021 ◽

Vol 57 (7) ◽

pp. 679

Author(s):

Monica Iuliana Ungureanu ◽

Liliana Sachelarie ◽

Radu Ciorap ◽

Bogdan Aurelian Stana ◽

Irina Croitoru ◽

...

Keyword(s):

Predictive Value ◽

Allergic Diseases ◽

Specific Ige ◽

Egg White ◽

Food Allergens ◽

Pediatric Hospital ◽

Disease Remission ◽

Specific Serum ◽

Different Types

Background and Objectives: Different types of food introduced gradually in the diet will expose children to different food allergens, increasing the chance of developing allergic diseases. The aim of our study was to determine if allergen-specific IgE values can influence, depending on the diet, the prediction of remission of urticaria in children. Materials and Methods: This prospective study was conducted in 132 patients diagnosed over two years with urticaria, admitted to “Sf. Maria” Clinical Pediatric Hospital Iaşi. Total IgE assay was performed by ELISA, and determination of specific serum IgE by the CLA System Quanti Scan method (Innogenetics, Heiden, Germany). Data were gathered and statistical analysis was performed using statistical software SPSS, using descriptive and inferential statistics. Results: The determination of specific IgE to food allergens was performed on a total of 132 cases. The values of specific IgE were positive for one or more food allergens in 84 patients (63.64%). The most common allergens involved were: cow’s milk in 33.3% cases, egg white in 22.6% cases, and hazelnuts in 11.9% cases. The specific IgE values for the different types of food included in our study had a predictive value for disease remission. Conclusions: The determination of specific IgE confirms the presence of a particular food allergen and may have predictive value for the future development of an allergic manifestation.

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