Peter E. Jackson

Ion chromatography : principles and applications

Chapter 1. Introduction. PART I. Ion-Exchange Separation Methods. Chapter 2. An introduction to ion-exchange methods. Chapter 3. Ion-exchange stationary phases for ion chromatography. Chapter 4. Eluents for ion-exchange separations. Chapter 5. Retention models for ion-exchange. PART II. Ion-Interaction, Ion-Exclusion and Miscellaneous Separation Methods. Chapter 6. Ion-interaction chromatography. Chapter 7. Ion-exclusion chromatography. Chapter 8. Miscellaneous separation methods. PART III. Detection Methods. Chapter 9. Conductivity detection. Chapter 10. Electrochemical detection (amperometry, voltammetry and coulometry). Chapter 11. Potentiometric detection. Chapter 12. Spectroscopic detection methods. Chapter 13. Detection by post-column reaction. PART IV. Practical Aspects. Chapter 14. Sample handling in ion chromatography. Chapter 15. Methods development. PART V. Applications of Ion Chromatography. Overview of the applications section. Chapter 16. Environmental applications. Chapter 17. Industrial applications. Chapter 18. Analysis of foods and plants. Chapter 19. Clinical and pharmaceutical applications. Chapter 20. Analysis of metals and metallurgical solutions. Chapter 21. Analysis of treated waters. Chapter 22. Miscellaneous applications. Appendix A. Statistical information on ion chromatography publications. Appendix B. Abbreviations and symbols. Index.

Optimization of inorganic capillary electrophoresis for the analysis of anionic solutes in real samples

Abstract Inorganic capillary electrophoresis (ICE) is a separation technique which offers many advantages for the analysis of anionic solutes in real samples. Parameters which influence ICE separations configuration, choice of electrolyte anion, electrolyte pH and the addition of electroosmotic flow modifier were investigated and a number of electrolytes of varying mobilities were studied. Optimized conditions were established for the separation of inorganic anions, organic acids and alkylsulfonates and the technique was applied to the analysis of a variety of anionic solutes in sevaral complex sample matrices.

Factors controlling ion-exchange selectivity in suppressed ion chromatography

The control of ion-exchange selectivity is the most important means of moderating separations in suppressed ion chromatography. Selectivity variations are primarily achieved through the use of different stationary phases, hence the construction of the stationary phase plays a key role. The major factors which determine the selectivity of the ion-exchange phase are: the polymer composition of the stationary phase, the type of ion-exchange site and the structure of the ion-exchange site. The eluent can also play a significant role in determining the overall selectivity of an ion-exchange separation. The mobile phase parameters which affect the separation selectivity are: the choice of eluent ion, the concentration (and pH) of the eluent, the presence of non-ionic eluent modifiers and the eluent temperature.

Applications of ion chromatography with electrospray mass spectrometric detection to the determination of environmental contaminants in water

Ion chromatography (IC) is widely used for the compliance monitoring of common inorganic anions in drinking water. However, there has recently been considerable interest in the development of IC methods to meet regulatory requirements for analytes other than common inorganic anions, including disinfection byproduct anions, perchlorate, and haloacetic acids. Many of these new methods require the use of large injection volumes, high capacity columns and analyte specific detection schemes, such as inductively coupled plasma mass spectrometry or postcolumn reaction with UV-Vis detection, in order to meet current regulatory objectives. Electrospray ionization mass spectrometry (ESI-MS) is a detection technique that is particularly suitable for the analysis of permanently ionized or polar, ionizable compounds. The combination of IC with MS detection is emerging as an important tool for the analysis of ionic compounds in drinking water, as it provides increased specificity and sensitivity compared to conductivity detection. This paper reports on the application of IC-ESI-MS for the confirmation and quantitation of environmentally significant contaminants, i.e. compounds with adverse health effects which are either regulated or being considered for regulation, such as bromate, perchlorate, haloacetic acids, and selenium species, in various water samples.

Capillary electrophoresis of inorganic ions and low-molecular-mass ionic solutes

Abstract While the majority of capillary electrophoresis (CE) applications to date have been concerned with the separation of biological molecules, this methodology also appears to be a viable alternative to ion chromatography (IC) for the determination of inorganic ions and other low-molecular-mass ionic solutes. CE offers a number of advantages over IC, including simplicity, greater separation efficiency, unique selectivity and a high degree of matrix independence, all of which make it ideal for the analysis of ionic solutes in complex samples.

Developments in suppressor technology for inorganic ion analysis by ion chromatography using conductivity detection.

A review is presented detailing the development and use of suppression devices for the conductimetric detection of inorganic ions by ion chromatography (IC). An overview of the general response equation for conductivity detection is also given. Topics of discussion include the role and function of suppressors, the development of early suppressors including packed column and membrane devices from 1975 to 1990 and the subsequent progression towards present day commercially available suppressors and recent innovations. Post-suppression devices for signal enhancement are also discussed.

Determination of inorganic cations and ammonium in environmental waters by ion chromatography with a high-capacity cation-exchange column.

While alkali and alkaline earth cations are commonly determined by using spectrometric techniques such as atomic absorption spectrometry or inductively coupled plasma, ammonium cation in the same sample must be measured separately by a wet chemical technique such as colorimetry, titrimetry, or ammonia-selective electrode. In a single 25-min run ion chromatography can determine all of the important inorganic cations including lithium, sodium, ammonium, potassium, magnesium and calcium. In this paper, we describe the use of ion chromatography with a new high-capacity cation-exchange column (the IonPac CS16), an electrolytically-generated methanesulfonic acid eluent and suppressed conductivity detection to determine dissolved alkali and alkaline earth cations and ammonium in drinking water wastewater and aqueous soil extracts. The IonPac CS16 is a high-capacity cation-exchange column that incorporates recent advances in polymer chemistry to enable trace-level determinations of cations even in high-ionic-strength matrices. We discuss the linear range, method detection limits, and analyte recoveries obtained with this column, and evaluate the effect of potential interferences on method performance during the analysis of typical environmental samples.

Determination of inorganic ions in drinking water by ion chromatography

Ion chromatography (IC) is now a well established methodology for the analysis of ionic species. The technique is applicable to the determination of a wide range of solutes in many sample types, although the determination of inorganic ions in drinking water continues to be the most widely used application of ion chromatography. Many regulatory and standard organizations, such as ASTM, AOAC, ISO, and US EPA, have approved methods of analysis based upon IC, most of which have been published within the last 10 years. Recent developments in the field of IC, such as the use of higher capacity columns, larger loop injections, more complex sample preparation and detection schemes, have been incorporated into new approved methods to allow the determination of inorganic contaminants, such as bromate, perchlorate, and chromate, at low μg/l levels in drinking waters. IC appears certain to remain an important technique for drinking water analysis and new methods based on IC will continue to be developed as more inorganic contaminants become regulated at lower limits in the future.

Determination of trace level perchlorate in drinking water and ground water by ion chromatography

Ammonium perchlorate, a key ingredient in solid rocket propellants, has recently been found in ground and surface waters in the USA in a number of states, including California, Nevada, Utah, and West Virginia. Perchlorate poses a health risk and preliminary data from the US Environmental Protection Agency reports that exposure to less than 4-18 micrograms/l provides adequate human health protection. An ion chromatographic method was developed for the determination of low microgram/l levels of perchlorate in drinking and ground waters based on a Dionex IonPac AS11 column, a 100 mM hydroxide eluent, large loop (1000 microliters) injection, and suppressed conductivity detection. The method is free of interferences from common anions, linear in the range of 2.5-100 micrograms/l, and quantitative recoveries were obtained for low microgram/l levels of perchlorate in spiked drinking and ground water samples. The method detection limit of 0.3 microgram/l permits quantification of perchlorate below the levels which ensure adequate health protection. A new polarizable anion analysis column, the IonPac AS16, and its potential applicability for this analysis is also discussed.

Critical comparison of retention models for optimisation of the separation of anions in ion chromatography III. Anion chromatography using hydroxide eluents on a Dionex AS11 stationary phase

Three ion chromatography (IC) retention models, namely the linear solvent strength model (LSSM), empirical end points model (EEPM) and three-point curve fitting using DryLab from LC Resources were evaluated in terms of their ability to predict retention factors for inorganic anions separated on a Dionex AS11 column using electrolytically generated hydroxide eluents. Extensive experimental retention data were gathered for 21 anions (fluoride, acetate, formate, bromate, chloride, nitrite, methanesulfonate, bromide, chlorate, nitrate, iodide, thiocyanate, succinate, sulfate, tartrate, oxalate, tungstate, phthalate, chromate, thiosulfate and phosphate) using hydroxide eluents of varying concentration. Although the purely theoretical LSSM was found to give adequate performance, the EEPM (in which a linear relationship is assumed between the logarithm of retention factor and the logarithm of eluent strength, but the slope is determined empirically) and DryLab performed better, with DryLab giving the best accuracy and precision of the three models. The EEPM and DryLab were also shown to have advantages in terms of their low knowledge requirements and ease of solution. Compared with IC using dual eluent species, the retention behaviour in IC using single eluent species was found to be easier to model by both theoretical and empirical approaches.