Determination Of Main Components Research Articles

Analysis of Highly Concentrated Aqueous Solutions of Alkali Metal Chlorides Using Sonoluminescence Spectroscopy.

The use of the sonoluminescence spectroscopy for the determination of main components in concentrated aqueous solution of alkali metal halides is examined. In concentrated RCl solutions (R = Li, Na, K; C = 100-600 g · dm-3) the sonoluminescence intensity is inversely proportional to ultrasound frequency in the range from 2 Hz up to 5 Hz. In the CsCl case the inverse proportionality is disturbed at ultrasound frequencies higher than 3 MHz. This is the limiting value for the accurate analysis of the concentrated solutions of cesium chloride. The increase of initiating ultrasound frequency leads to a decrease of the main component determination in highly concentrated (more than 300 g ċ dm-3) natural and artificial solutions. Nevertheless, the metrological characteristics of the results of the main substance determination in these solutions improve. The routines of express determination of the main substance in concentrated saline solutions were developed.

Quantitative aspects of microchip isotachophoresis for high precision determination of main components in pharmaceuticals.

Although microchip electrophoresis (MCE) is intended to provide reliable quantitative data, so far there is only limited attention paid to these important aspects. This study gives a general overview of key aspects to be followed to reach high-precise determination using isotachophoresis (ITP) on the microchip with conductivity detection. From the application point of view, the procedure for the determination of acetate, a main component in the pharmaceutical preparation buserelin acetate, was developed. Our results document that run-to-run fluctuations in the sample injection volume limit the reproducibility of quantitation based on the external calibration. The use of a suitable internal standard (succinate in this study) improved the repeatability of the precision of acetate determination from six to eight times. The robustness of the procedure was studied in terms of impact of fluctuations in various experimental parameters (driving current, concentration of the leading ions, pH of the leading electrolyte and buffer impurities) on the precision of the ITP determination. The use of computer simulation programs provided means to assess the ITP experiments using well-defined theoretical models. A long-term validity of the calibration curves on two microchips and two MCE equipments was verified. This favors ITP over other microchip electrophoresis techniques, when chip-to-chip or equipment-to-equipment transfer of the analytical method is required. The recovery values in the range of 98-101 % indicate very accurate determination of acetate in buserelin acetate, which is used in the treatment of hormone-dependent tumors. This study showed that microchip ITP is suitable for reliable determination of main components in pharmaceutical preparations.

Odor Abatement in Biotrickling Filters for Wastewater Treatment Plants in Petrochemical Industries: Determination of Main Components of VOCs and Assessment of REs

A biotrickling filter has been set up in WWTP of Nanjing petrochemical factory for about 6 months. The purpose of this project was to assess the ability of the biotrickling filter to remove hardly biodegradable VOCs such as benzene, toluene, ethylbenzene and xylene which are recalcitrant and poorly water soluble and commonly found in petrochemical factories. PUF cubes (1 cm3) were used as the packing media treated with large amounts of circulating mineral salt medium added with bacterial species which came from secondary sedimentation tank of WWTP of Nanjing petrochemical industry. The controlled empty bed retention time (EBRT) of 90 s was a key parameter for reaching a removal efficiency of 91.7 %, 88.3 %, 70.7 % and 63.5 % for toluene, ethylbenzene, benzene and xylene, respectively. The analysis of the bacterial community in the BTF during VOC removal showed that Pseudomonas putida and Klebsiella sp. phylum were dominant microbes.

Determination of Main Components in the Excess Activated Sludge

In the study, we determine the content of the main components, i.e., protein, polysaccharides and lipids in the excess activated sludge. The measurement results were consistent with those obtained before. In conclusion, the research indicated that the waste activated sludge consisted of 73.85% organic matter, 58.1% protein, 10.39 mg/g carbohydrate, less than 1% lipid.

Near Infrared and Mid Infrared Spectroscopy in Oenology: Determination of Main Components Involved in Malolactic Transformation

Near Infrared and Mid Infrared Spectroscopy in Oenology: Determination of Main Components Involved in Malolactic Transformation

Determination of main components in the extracellular polymeric substances extracted from activated sludge using a spectral probing method

In this study, a spectral probing method was applied to determine the content of the main components, i.e., proteins, polysaccharides and humic substances, in the extracellular polymeric substances (EPS) extracted from activated sludge. The measurement results were consistent with those obtained from the conventional methods, such as the anthrone for polysaccharide determination, the modified Lowry method for protein and humic substance determination. The recoveries for the determination of proteins, humic substances and polysaccharides in the EPS extracted from six sludge samples using standard additional method were between 92.4 and 108.9%, 84.8 and 108.9%, 75.1 and 117.2%, respectively. These results indicate that the propose method has a good accuracy and precision, and can be used as an effective approach to determine the main components in sludge EPS.

Determination of main components and anaerobic rumen digestibility of aquatic plants in vitro using near-infrared-reflectance spectroscopy

A near-infrared-reflectance (NIR) spectroscopy-based method is established to determine the main components of aquatic plants as well as their anaerobic rumen biodegradability. The developed method is more rapid and accurate compared to the conventional chemical analysis and biodegradability tests. Moisture, volatile solid, Klason lignin and ash in entire aquatic plants could be accurately predicted using this method with coefficient of determination ( r 2) values of 0.952, 0.916, 0.939 and 0.950, respectively. In addition, the anaerobic rumen biodegradability of aquatic plants, represented as biogas and methane yields, could also be predicted well. The algorithm of continuous wavelet transform for the NIR spectral data pretreatment is able to greatly enhance the robustness and predictive ability of the NIR spectral analysis. These results indicate that NIR spectroscopy could be used to predict the main components of aquatic plants and their anaerobic biodegradability.

Determination of main components and impurities in lithium-boron alloys

Determination of main components and impurities in lithium-boron alloys