Anions chemical analysis

J. Cross, ed.. Anionic Suf actants. Chemical Analysis, Suf actant Science Series, Vol. 8, Marcel Dekker, Inc., New York, 1977. 

Oxygen corrosion involves many accelerating factors such as the concentration of aggressive anions beneath deposits, intermittent operation, and variable water chemistry. How each factor contributes to attack is often difficult to assess by visual inspection alone. Chemical analysis of corrosion products and deposits is often beneficial, as is more detailed microscopic examination of corrosion products and wasted regions. 

Pretreatment of the collected particulate matter may be required for chemical analysis. Pretreatment generally involves extraction of the particulate matter into a liquid. The solution may be further treated to transform the material into a form suitable for analysis. Trace metals may be determined by atomic absorption spectroscopy (AA), emission spectroscopy, polarogra-phy, and anodic stripping voltammetry. Analysis of anions is possible by colorimetric techniques and ion chromatography. Sulfate (S04 ), sulfite (SO-, ), nitrate (NO3 ), chloride Cl ), and fluoride (F ) may be determined by ion chromatography (15). 

Figure 14-9 also shows a flowchart for analysis of wet and dry precipitation. The process involves weight determinations, followed by pH and conductivity measurements, and finally chemical analysis for anions and cations. The pH measurements are made with a well-calibrated pH meter, with extreme care taken to avoid contaminating the sample. The metal ions Ca, Mg, Na, and are determined by flame photometry, which involves absorption of radiation by metal ions in a hot flame. Ammorda and the anions Cl, S04 , NO3 , and P04 are measured by automated colorimetric techniques. 

Anionic Surfactants Chemical Analysis, edited by John Cross... 

Ion chromatography permits the determination of both inorganic and organic ionic species, often in concentrations of 50 g L"1 (ppb) or less. Since analysis time is short (frequently less than 20 minutes) and sample volumes may be less than 1 mL, IC is a fast and economical technique. It has found increasing application in a number of different areas of chemical analysis and particularly for the quantitative determination of anions. The state-of-the-art has been reviewed.26... 

Emulsions and Emulsion Technology (in three parts), edited by Kenneth J. Lissant Anionic Surfactants (in two parts), edited by Warner M. Linfieid see Volume 56) Anionic Surfactants Chemical Analysis, edited by John Cross Stabilization of Colloidal Dispersions by Polymer Adsorption, Tatsuo Sato and Richard Ruch... 

The ESA spectra of asymmetrical dyes in toluene are shown in Fig. 25. They show broad structureless bands in the NIR region (750-1,100 nm for G19, 850-1,100 nm for G40, and 950-1,100 nm for G188) and more intense transitions in the visible range (400-550 nm for G19, 400-600 nm for G40, and 450-650 nm for G188). Similarly to symmetrical anionic polymethine dyes (Fig. 20), the increase of conjugation length leads to a small red shift of ESA spectra, and to an enhancement of ESA cross sections and the ratio between the ESA and linear absorption oscillator strengths by approximately a factor of two. More detailed experimental description and quantum-chemical analysis can be found in [86]. 

With the aim of minimising the time taken in the preconcentration, and extending the chemical analysis of surfactants to more complex aqueous matrices in which very low detection limits are required, preconcentration techniques using solid-liquid extraction with various adsorbent materials, such as XAD [27] and anionic exchange resin [28] have been developed. 

These compounds can initiate anionic polymerisation of epoxides, and when R, = H the secondary amine can react by addition to an epoxide group. Farkas and Strohm 64> have studied the reaction of 2-ethyl-4-methyl imidazole with phenyl glycidyl ether and BADGE resin using chemical analysis and proton NMR spectroscopy. They found that the imidazole readily forms adducts with epoxide of 1 1 and 1 2 molecular ratio ... 

Chemical analysis for cation composition, cation/anion ratio, and chemical impurities. 

Cross, J. (Ed.), Anionic Surfactants — Chemical Analysis, Dekker New York, 1977. 

The anionic groups observed in basement membrane with cationic stains were identified as heparan sulfate chains on the basis of their sensitivities to heparitinase and to nitrous acid (Kanwar and Farquhar, 1979b) and by chemical analysis (Kanwar and Farquhar, 1979c Parthasarathy and Spiro, 1982). Current concepts suggest that the heparan sulfate chains are linked through a common oligosaccharide terminating in xylose linked to serine residues on the protein core and that certain xylosides can act as initiators for the synthesis of heparan sulfate. In the absence of added xyloside, the synthesis of heparan sulfate is entirely dependent on the synthesis of a core protein. 

In a previous study we have found that, at low temperature, PS-I electron transfer is largely blocked away from A, and that the state (P-700+, A, ) decays with a half-time of 130us. Analysis of the absorption spectrum of that state showed that A, is presumably a quinone radical anion (Brettel et al, 1986). Chemical analysis, following separation by HPLC, has shown that phylloquinone (a naphthoquinone also named vitamin Kj) is the only quinone present in PS-I. We have found 2 moles of phylloquinone per PS-I. Extraction with dry hexane does not change the electron transfer reactions this treatment only extracts only one phylloquinone per PS-I (Biggins and Mathis, 1987). 

Scott W., and Furman, N. H. (ed.). 1961. Scott s Standard Methods of Chemical Analysis (5th ed., vol. 1, pg. 604). Princeton, NJ D. Van Nostrand Company Inc. Shibasaki-Kitakawa, N., Honda, H., Kuribayashi, H., Toda, T., Fukumura, T., and Yonemoto, T. 2007. Biodiesel production using anionic ion-exchange resin as heterogeneous catalyst. Bioresour. Technol., 98(2), 416-421. 

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