Joseph F. Dlouhy

Application of capillary electrophoresis in atmospheric aerosols analysis : determination of inorganic and organic anions

The usefulness of capillary electrophoresis in the analysis of inorganic and organic anions in atmospheric aerosols was investigated. Various electrolytes based on chromate, pyromellitate (PMA), phthalate and 2,6-naphthalenedicarboxylate (NDC) were tested. Two separate electrolyte systems (PMA and NDC) are recommended for determination of anions with different mobility. Results obtained by parallel analysis of sulphate by capillary electrophoresis and ion chromatography in atmospheric aerosols are presented.

Capillary zone electrophoresis with indirect UV detection of organic anions using 2,6-naphthalenedicarboxylic acid

2,6-Naphthalenedicarboxylic acid (NDC) was characterized as a carrier electrolyte for a separation of organic anions by capillary zone electrophoresis (CZE) with indirect UV detection. Parameters which influence CZE separations such as concentration of NDC, electrolyte pH and various electroosmotic flow modifiers were investigated. The sensitivity obtained with the NDC electrolyte was five times higher than with phthalate, which is commonly used for the separation of organic anions. This method was applied to the determination of organic anions in the ambient air.

Application of capillary electrophoresis in atmospheric aerosol analysis: determination of cations

Abstract The feasibility of using capillary electrophoresis (CE) with a new electrolyte system for the analysis of alkali metal, alkaline-earth metal cations and ammonium in atmospheric aerosols has been demonstrated. 1,1′-Di-n-heptyl-4,4′-bipyridinium (DHPB) hydroxide was used as the UV-absorbing species, which allowed for the indirect UV detection of cations at 280 nm, while glycine, 18-crown-6 ether and methanol were employed to improve the separation of the studied cations. The precision of migration time and peak area was better than 0.2% and 5%, respectively. Separation efficiencies were between 90 000 and 600 000 theoretical plates per meter, and detection limits between 9 and 60 ng/ml. With the described electrolyte composition it is also possible to determine manganese and cadmium, and short-chain aliphatic amines. The comparison of CE results with ion chromatography obtained for cations in atmospheric aerosols is presented.

Automatic simultaneous determination of anions and cations in atmospheric aerosols by ion chromatography

The application of an automatic quadruple ion chromatography system for the simultaneous determination of inorganic and organic anions, and inorganic cations in atmospheric aerosol extracts using a total volume of 5 ml is described. The automation of the analysis via a single loading system and analysis by anion isocratic, anion gradient (with and without preconcentration) and cation gradient methods with chemical suppression and conductometric detection is presented. Comparison of anion results obtained by the respective methods is shown.

Comparison of capillary zone electrophoresis with ion chromatography and standard photometric methods for the determination of inorganic anions in atmospheric aerosols

Abstract The capillary zone electrophoresis (CZE), ion chromatography and photometric techniques were compared for the analysis of nitrate and sulphate in high-volume sampled atmospheric aerosols. The CZE method with indirect UV detection utilizing a pyromelliate-based electrolyte was used. The comparative evaluation included response stability of instruments, detection limits, accuracy, precision, analysis time and other operational considerations. Statistical analysis of the results indicated that there was no evidence for systematic differences between the three techniques. The results suggest that CZE can be applied very advantageously in an anion analysis in atmpospheric aerosols.

Routine determination of major anions in atmospheric aerosols by capillary electrophoresis

Abstract Capillary electrophoresis (CE) with indirect UV detection utilizing a pyromellitate-based electrolyte was used for the routine analysis of major anions in atmospheric aerosols collected on filters with high-volume (Hi-Vol) samplers. The long-term reliability of the CE system was checked over an 8-month period during which over 2900 samples were analyzed. In addition, approximately 1100 samples were analyzed in parallel by ion chromatography (IC). It has been shown that acceptable analytical performance can be routinely obtained. The agreement between the CE and IC results is good, generally better than 20% at concentrations larger than 1 mg l −1 .

Simultaneous determination of alkali, alkaline-earth metal cations and ammonium in environmental samples by gradient ion chromatography

A gradient ion chromatographic method with chemical suppression is described for the simultaneous determination of alkali, alkaline-earth metal cations and ammonium. This fully automated ion chromatographic method was applied to determine these cations in water extracts of ambient air particulates collected on thin PTFE filters. The procedure is also potentially available for any aqueous samples.