Results 261 to 270 of about 75,845 (309)

Chemical Oxygen Demand Using Closed Microwave Digestion System

Environmental Science & Technology, 2005
A new approach to determine the chemical oxygen demand (COD) using a closed microwave digestion (CMD) system to replace the conventional, time-consuming open reflux (OR) method is proposed. The procedure uses a laboratory-grade closed microwave digestion system (one magnetron) for the digestion of small volume of samples (3.0 mL) in a completely closed
Dattatray M, Dharmadhikari, Atul P, Vanerkar, Nivedita M, Barhate   +2 more
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Microwave-Assisted Enzymatic Digestions

2009
Despite advances in “top-down” mass spectrometric methods for characterizing proteins, the traditional “bottom-up” approach of digesting a protein into smaller peptides followed by either peptide mass fingerprinting or reverse-phase separation and tandem mass spectrometric identification remains the most widely employed analytical method for protein ...
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Ultrafast Microwave-Assisted In-Tip Digestion of Proteins

Journal of Proteome Research, 2009
Trypsin was immobilized on glycidylmethacrylate-co-divinylbenzene (GMA/DVB) polymerized in pipet tips for online enzymatic digestion of proteins. The major advantages of in-tip digestion are easy handling and small sample amount required for analysis. Microwave-assisted digestion was applied for highly efficient and time saving proteolysis. Adaption to
Hans W, Hahn, Matthias, Rainer, Thomas, Ringer, Christian W, Huck, Günther K, Bonn   +4 more
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Digestion of Titanium Bearing Geologic Materials Involving Microwaves

Annali di Chimica, 2007
AbstractAn environmentally friendly and rapid digestion procedure involving 10 mL of acid mixture (HNO3 : HCl : HF = 2:2:1) for 0.1 g of sample in closed vessel microwave digester following heating program : 250W for 10 min., hold time 2 min., 600 W for 17 min, and Ventilation time 10 min was developed.
Anju, Tripathi, Partha, Chattopadhyay
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Acid digestion of geological and environmental samples using open-vessel focused microwave digestion

Analytical and Bioanalytical Chemistry, 2002
The application of open vessel focused microwave acid digestion is described for the preparation of geological and environmental samples for analysis using inductively coupled plasma-mass spectrometry (ICP-MS). The method is compared to conventional closed-vessel high pressure methods which are limited in the use of HF to break down silicates.
Vivien F, Taylor, Andrew, Toms, Henry P, Longerich   +2 more
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Reflux pre-digestion in microwave sample preparation

The Analyst, 1993
In order to prevent excessive pressure rises in closed microwave acid digestion of fairly large (1 g) samples of high organic content, an open-vessel pre-digestion technique under reflux was designed to allow the escape of oxidation products, such as carbon dioxide, without incurring evaporation losses of acid or analytes.
Helen J. Reid, Stanley Greenfield, Tony E. Edmonds, Rafiq M. Kapdi   +3 more
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Recovery of polonium from microwave bomb digestions

Analytica Chimica Acta, 1994
Abstract The use of microwave digestion of plant and animal tissue in preparation for measurement of the volatile element polonium was evaluated. Digestion in concentrated nitric acid in a closed vessel at up to 1380 kPa took up to 2 h. The nitric acid was removed by evaporation in an open beaker and the Po transferred to hydrochloric acid.
P.H. Towler, J.D. Smith
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Communication. Liquid nitrogen cooling in microwave digestion

The Analyst, 1993
In an attempt to minimize the delay in opening Teflon pressure vessels following microwave acid digestion, and thus significantly reduce sample preparation time, various approaches to vessel cooling have been investigated. These include the feasibility of carrying out digestions with the pressure vessels immersed in liquid nitrogen and the use of ...
Helen J. Reid, Stanley Greenfield, Tony E. Edmonds   +2 more
openaire   +1 more source

Microwave-Assisted Chemical Digestion of Proteins

2009
Chemical proteolysis is often employed as an alternative or complementary analytical tool to enzyme-mediated proteolysis for the characterization of proteins by mass spectrometry. Acids and other chemicals can be selected to cut at either specific amino acid residues or at chemically labile sites of a protein and may offer a harsher alternative ...
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Semimicro Determination of COD Employing Microwave Digestion

Environmental Engineering Science, 2003
A modified semimicro method is described for determining chemical oxygen demand (COD) employing microwave (MW) digestion (0.5 min exposure at 1,000 W power, and 10 min exposure at 250 W power) with a titration assessment. Composition of reaction mixture was the same as that of the usual reflux method.
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