Electrochemistry elemental analysis

Keywords National traceability system Chemical calibration laboratories Clinical chemistry Electrochemistry Elemental analysis Gas analysis... 

Manager, Analytical Research in Shell Development s Analytical Department of 175 people. Moved to Houston, Texas in 1972 with the consolidation of Shell s research activities there. Responsible for program generation, technical excellence and relevance of all broadly based analytical research. Accountable for annual budget of 1,300,000 (in 1975 dollars). Research spanned the entire analytical field Separations, molecular spectroscopy, physical measurements, organic analysis, electrochemistry, elemental analysis, etc. Initiated programs in a number of new techniques... 

Atomic Spectrometry Chromatography Distillation Electrochemistry Elemental Analysis, Organic Compounds Gas Chromatography Infrared Spectroscopy Liquid Chromatography... 

Khaleel M.M.A., Lin Z., Singh P., Surdoval W., Collin D., 2004. A finite element analysis modeling tool for solid oxide fuel cell development Coupled electrochemistry, thermal and flow analysis in MARC. Journal of Power Sources 130, 136-148. 

Lin, Z., Khaleel, M., Surdoval, W. and Collins, D. (2003) Finite element analysis of solid oxide fuel cells Coupled electrochemistry, thermal and flow analysis in MARC, in Proceedings SECA Modeling and Simulation Training Session, Morgantown, WV, August 29, 2003. 

At present the traceability system consists of structures (traceability chains) in the fields of clinical chemistry, electrochemistry and gas analysis. A traceability structure for elemental analysis is under development. Figure 1 shows the structural principle of the traceability system, which is applied to all the fields mentioned. 

General methods for the certification of RMs for elemental content are based on atomic absorption spectrometry (FAAS, ETAAS, HG-AAS, CV-AAS), atomic emission spectrometry (FAES, ICP-AES, HG-ICP-AES, DCP-AES), atomic fluorescence spectrometry (CV-AFS), mass spectrometry (IDMS, SSMS, NAMS, ICP-MS), nuclear methods (IPAA, PAA, INAA, RNAA), X-ray emission (EDXRF, WDXRF, particie induced techniques), light-absorption spectrometry (LAS, FL), electrochemistry (ASV, CSV, DPP, ISE) and other methods (Kjeldahl, combustion elemental analysis, volumetry, chromatography, gravimetry) [32]. Certification of BCR-680/681 was carried out by sixteen participating laboratories using a variety of common as well as highly specialised techniques (Table 8.10). 

With the increased computational power of today s computers, more detailed simulations are possible. Thus, complex equations such as the Navier—Stokes equation can be solved in multiple dimensions, yielding accurate descriptions of such phenomena as heat and mass transfer and fluid and two-phase flow throughout the fuel cell. The type of models that do this analysis are based on a finite-element framework and are termed CFD models. CFD models are widely available through commercial packages, some of which include an electrochemistry module. As mentioned above, almost all of the CFD models are based on the Bernardi and Verbrugge model. That is to say that the incorporated electrochemical effects stem from their equations, such as their kinetic source terms in the catalyst layers and the use of Schlogl s equation for water transport in the membrane. 

With his colleague Louis-Jacques Thenard (1777-1857), Gay-Lussac did considerable work with electrochemistry to produce significant amounts of elemental sodium and potassium, highly reactive and useful substances that were used to isolate and discover the element boron. Gay-Lussac also completed extensive studies of acids and bases and was the first to deduce that there were binary (two element) acids such as hydrochloric acid (HC1) in addition to the known oxygen-containing acids like sulfuric acid (H2S04). Additionally, he was able to determine the chemical composition of prussic acid to be hydrocyanic acid (HCN) and was considered the foremost practitioner of organic analysis. 

Cai, W.J., Zhao, R, Theberge, S.M., Wang, Y., and Luther III, G (2002) Porewater redox species, pH and PCO2 in aquatic sediments—electrochemical sensor studies in Lake Champlain and Sapelo Island. In Environmental Electrochemistry Analysis of Trace Element Biogeochemistry (Taillefert, M., and Rozan, T., eds.), pp. 188-209, American Chemical Society, Washington, DC. 

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