Anions and organic acids

FIGURE 6 Analysis of UV-absorbing anions and organic acid is possible with a 70mM phosphate buffer at pH 2.5. 

I. Buffers for Anions and Organic Acids with Indirect UV Detection... 

We have seen that a BGE for analysis of anions and organic acids needs to have (a) a pH above the p A 2 of the analyte, (b) a sufficient buffering effect, and (c) a co-ion as a probe for indirect UV detection, with mobility close to that of the analytes of interest. Furthermore, care should be taken to reverse the EOF of the capillary and to work in the anodic or reverse mode. 

Anon (n.d.e) Dionex application note number 123 The determination of inorganic anions and organic acids in fermentation broths. Available as a downloadable file from the Dionex website (http //www.Dionex.com). 

Ion chromatography is the method of choice for the analysis of trace and ultratrace levels of inorganic anions. It is also important for the simultaneous separation of inorganic anions and organic acids. Although IC is... 

Ion-exclusion chromatography can couple to ion chromatography to improve the chromatographic resolution of inorganic anions and organic acids in complex matrices. The dual system can be either in the order lEC/IC or IC/IEC. 

There are also stationary phases that effectively partition solutes in either reversed-phase or normal-phase mode. These stationary phases are typically silica particles derivatized with cyano, diol, or amino functional groups. Particles with a cyano-functionality separate based on polarity utilizing nitrile interactions between the stationary phase and the solute. The amino group of typical amino stationary phases interacts primarily with anionic and organic acid portions of the solute. Diols utilize hydroxyl interactions similar to underivatized silica but offer a slightly different selectivity. These and other bonded-silica phases offer alternatives to underivatized silica, but they are used much less frequently. The mobile phases employed with these stationary phases are the same as used in standard reversed-phase or normal-phase chromatography. 

Altered, and injected directly. Inorganic anions and organic acids such as oxalic acid, which are contained in spinach, may be analyzed in less than 10 minutes. As in many... 

ICSep AN2 lonPac ASH Isocratic. separation of anions and organic acids and solvent compatible... 

Toofan, M., Stillian, J. R., Pohl, C. A., and Jackson, P. E., Preconcentration determination of inorganic anions and organic acids in power plant waters. Separation optimization through control of column capacity and selectivity, J. Chromatogr. A, 761, 163-168, 1997. 

AS 15 High Trace levels of inorganic anions and organic acids in high-purity water samples. 

The breakthrough in the development of organic polymer monoliths for use in conventional anion-exchange chromatography of common inorganic anions and organic acids was made possible by several new advancements including as follows ... 

Figure 10.222 Gradient elution of inorganic anions and organic acids in wine. Separator column lonPac AS11-HC with guard column temperature 30 °C eluent NaOH/MeOH gradient 1 mmol/L NaOH isocratically for 8 min and then linearly to 30 mmol/L in 20 min and to 60 mmol/L in 10 min, 0-20% MeOH from 8 to 18 min, 20% from 18 to 28 min, and 20-0% from 28 to 38 min flow rate 1.5mL/min ...

Toofan, M. et al.. Preconcentration determination of inorganic anions and organic acids in power plant waters, /. Chromatogr. A, 761,163,1997. 

Rate constants were determined for a number of bimolecular photoreactions of hydroxy- and aminoaromatic compounds and heteroaromatic compounds with carboxylate anions and organic acids, respectively, in various micelles. Such bimolecular photoreactions were found to improve the efficiency of forward proton transfer reactions and to reduce reverse recombination of the primary products ( up to 2 orders of magnitude ) comparatively to aqueous solutions. 

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