Microwave decomposition

The most universal method for sample destmction before SPh metal determination (Ee, Mo, A1 and etc.) is the sulfur acid digestion at high temperature by Kjeldall. It can be enforced by microwave decomposition in the microwave oven. 

SELECTION OF CONDITIONS OF SOIL MICROWAVE DECOMPOSITION FOR ICP-MS ANALYSIS... 

Principles and Characteristics Instead of thermal initiation, microwave decomposition may be of use for sample preparation involving combustion or acid digestion. The advantages over thermal initiation lie in the shorter time needed (minutes instead of hours). Microwave oven digestion (MOD) systems are not analytical instruments. Functionally, they are chemical... 

Methods for disposing of diisopropyl methylphosphonate include microwave decomposition, ultraviolet and infrared laser-induced photodestruction, chemical oxidation coupled with ultraviolet radiation catalyzation, and adsorption using granular activated carbon (Bailin et al. 1975 Calgon 1977 ... 

Bailin LJ, Sibert ME, Jonas LA, et al. 1975. Microwave decomposition of toxic vapor simulants. Environmental Science and Technology 9(3) 254-258. 

Microwave Decomposition (Prolabo Microdigest) Automated Wet Decomposition Device VAO... 

The first robotically controlled microwave decomposition system was developed at Kidd Creek Mines in Canada. This first application described by Labrecque [23] was developed for the decomposition of geological samples in order to analyse the matrix and trace elements. 

Very recently, a novel microwave-assisted high-temperature UV digestion system for accelerated decomposition of dissolved organic compounds or slurries was developed [95, 96]. The technique is based on a closed, pressurized, microwave decomposition device wherein UV irradiation is generated by immersed electrodeless Cd discharge lamps (228 nm) operated by the microwave field in the oven cavity. The immersion system enables maximum reaction temperatures of up to 250-280 °C, resulting in a tremendous increase in mineralization efficiency. 

One of the main advantages of microwave decomposition compared with conventional methods using a flame or a hot plate (regardless of whether an Open or a... 

Figure 36-1 A moderate-pressure vessel for microwave decomposition. (Courtesy of CEM Corp., Matthews, NC.)...

Figure 36-2 A bomb for high-pressure microwave decomposition. (Courtesy of Parr Instrument Co., Moline IL.)...

Give three major advantages of microwave decompositions. 

A particular care was also recommended for the digestion of the lichen material. A systematic comparison of three microwave-decomposition techniques (with quartz vessels) using HNO3 at 170°C demonstrated that a high pressure (85 bar) and an addition of HF was necessary to obtain a complete recovery of As in this material. The use of a high pressure (85 bar) mode and a medium pressure (10 bar) mode without addition of HF led respectively to As contents 35% and 70% lower than the one found with the high pressure/HF method. It was suspected that an adsorption effect of arsenic on the surface of the quartz vessels could have occurred, which was avoided by HF addition. All other sets of data were accepted for certification. 

Food and Plant CRMs, RMs Zn Microwave decomposition with HNO3 in dosed vessel [WDMCV] Ion exchange, ICPMSr [SEP/CONC-ICP-MS] [WDMCV-SEP/ CONC-ICP- MS[ Mestek et al. (2001)... 

Paudyn am and Smith RG (1992) Microwave decomposition of dusts, ashes, and sediments for the determination of dements by ICP-AES. Can J Appl Spectrosc 37 94-99. 

Sample preparation for the determination of chemical elements stationary forms, associated with the various soil components was performed to obtain the acid extracts in the microwave decomposition system under pressure Speedwave MWS-2 (made in Germany BERGHOF Products + Instraments GmbH), using the individually selected mode. This process applies extra pure HNOj and HCL acids, which additionally underwent the distillation in the purification system BSB-939-IR. 

For determination of trace metals in human specimens it is not possible to state general valid regulations. Every clinical question signifies a separate analytical problem. The analytical procedure depends on the trace metal to be determined, the material, and the concentration of trace metal in the sample. However, AAS generally is limited to liquid samples, so that the material must be decomposed. Different decomposition techniques are used, e.g., wet ashing, pressure decomposition, microwave decomposition, and dry ashing followed by dissolution with water or acids [30]. Another disadvantage of AAS is the fact that within each series only one element can be determined. 

Microwave decomposition at atmospheric pressure can also be used as an on-line technique, e.g., in a way that the sample passes through a PTFE coil with an inner diameter of about... 

Wang, C. E, Chen, W. H.,Yang, M. H., and Chiang, P. C. (1995). Microwave decomposition for airborne particulate matter for the determination of trace elements by inductively coupled plasma mass spectrometry. Analyst (London) 120(6), 1681. 

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