Chemical multi-component analysis

Analysis strategies that use on-line ESI-LC/MS approaches provide an integrated format for natural product dereplication by combining traditional fraction collection, sample preparation, and multi-component analysis into a single step. In this way, crude extracts are screened without extensive purification and chemical analysis. Furthermore, less material is required due to the sensitivity of the technique and chromatographic resolution is retained. 

Vaihinger S. andGopelW, Multi-component analysis in chemical sensing, in A... 

Zarrouk, W., Carrasco-Pancorbo, A., Zarrouk, M., Segura-Carretero, A. and Fernandez-Gutierrez, A. (2009) Multi-component analysis (sterols, tocopherols and triterpenic dialcohols) of the unsaponifiable fraction of vegetable oils by liqnid chromatography-atmospheric pressure chemical ionization-ion trap mass spectrometry. Talanta 80, 924-934. 

HGSystem offers the most rigorous treatments of HF source-term and dispersion analysis a ailable for a public domain code. It provides modeling capabilities to other chemical species with complex thermodynamic behavior. It treats aerosols and multi-component mixtures, spillage of a liquid non-reactive compound from a pressurized vessel, efficient simulations of time-dependent... 

ICP-AES and ICP-MS analyses are hampered in almost all cases by the occurrence of sample matrix effects. The origins of these effects are manifold, and have been traced partly to physical and chemical aerosol modifications inside sample introduction components (nebulisation effects). Matrix effects in ICP-AES may also be attributed to effects in the plasma, resulting from easily ionised elements and spectral background interferences (most important source of systematic errors). Atomic lines are usually more sensitive to matrix effects than are ionic lines. There exist several options to overcome matrix interferences in multi-element analysis by means of ICP-AES/MS, namely ... 

Chapter 10 provides an exhaustive description of how these techniques can be applied to a large number of industrial alloys and other materials. This includes a discussion of solution and substance databases and step-by-step examples of multi-component calculations. Validation of calculated equilibria in multi-component alloys is given by a detailed comparison with experimental results for a variety of steels, titanium- and nickel-base alloys. Further selected examples include the formation of deleterious phases, complex precipitation sequences, sensitivity factor analysis, intermetallic alloys, alloy design, slag, slag-metal and other complex chemical equilibria and nuclear applications. 

Analytical Methods. Many chemical and physical analysis methods exist to characterize particulate matter collected on a substrate. Though several methods are multi-species, able to quantify a number of chemical components simultaneously, no single method is sufficient to both quantify the maiorlty of the collected particulate matter mass and those components which serve to Identify and quantify source contributions. 

In addition to the Drosophila sex pheromone CHCs mentioned above, it is well known that CHCs are used by ants for various chemical communications nestmate recognition, caste discrimination, etc. (see related chapters). In various ant species, chemical analysis of the body surface materials suggested that the colony-specific blends of a multi-component CHC mixture act as the nestmate-discriminative pheromone (Bonavita-Cougourdan et al., 1987 Yamaoka, 1990 Howard, 1993 Vander Meer and Morel, 1998 Howard and Blomquist, 2005). In a Japanese carpenter ant, Camponotus japonicus, the CHC pheromone, consisting of 18 CHC components of 20-40 carbons, is used as a chemical cue for nestmate and non-nestmate discrimination (Yamaoka, 1990). Because of the antennation behavior for inspecting encountered ants, the CHC-sensitive sensillum was expected to be discovered on the antenna. 

An alternative, at least semi-quantitative method to follow changes in biomass composition is infrared (IR) spectroscopy [22]. From dried samples of microbial cells, IR spectra can be obtained which contain information on all major cell components. The spectra are analysed as a multi-component mixture Characteristic bands in the spectra are identified, the extinction coefficients for each component (protein, carbohydrate, lipid, and nucleic acids) at each band are determined, and the concentrations are calculated by a system of linear equations. The method gives results on all major cell components simultaneously, and is relatively quick and easy to perform, compared to the chemical analysis methods. For details see Sect. 8.4 below. 

An extension to multi-component systems is straightforward, by injecting more than one component. A prerequisite is the measurement of the concentration profile of each solute during the elution. This can be achieved either by using solute-specific detectors or by collection of multiple fractions and subsequent chemical analysis... 

In this chapter we have applied the methods of chapter 4 to ionic equilibria other than those between acids and bases. Of course, complexation, extraction, solubility, precipitation, and redox equilibria may also involve acid-base equilibria, which is why we treated acid-base equilibria first. The examples given here illustrate that the combination of exact theory with the computational power of a spreadsheet allows us to solve many problems that occur in quantitative chemical analysis, and to analyze experimental data accordingly. Even quite complicated titrations, such as the multi-component precipitation titrations, the von Liebig titration, and redox titrations involving many species and complicated stoichiometries, can be handled with ease. 

For the more instrumental methods of quantitative chemical analysis, I have taken a rather eclectic approach, merely illustrating some aspects that are especially suitable for spreadsheet exploration, such as Beer s law and its applications to the analysis of multi-component mixtures, chromatographic plate theory, polarography, and cyclic voltammetry. 

The evaporation processes of the brines were studied by means of a physical-chemical analysis of the solubilities in multi-component systems, in the S component system ... 

---