Peak analysis in gas chromatography and the development of new stationary phases for anion chromatography

Abstract

<p>Causes of band broadening in capillary, gas chromatography are investigated. Using the Golay equation, it is shown that the presence of a diluent significantly increases the extra-column variance, in early eluting peaks, when a liquid injection is used. The cause of this phenomenon is also discussed;A mathematical method based on an iterative method is developed to obtain the correct hold-up time of a capillary column using a flame ionization detector. This method takes advantage of the programmable ability of a common, hand-held calculator. Also discussed is the application of this method for calculating Kovats indices and the calculation of capacity factors;The injection peak in single-column, anion exchange chromatography is used to quantitatively determine simple mixtures of cations in solution. By preparing the sample so that it contains the same concentration and pH value of eluent ions as the mobile phase, it is shown that the injection peak area is proportional to the concentration of cations and dependent on the type of cation present. Binary mixtures of salts in the presence of moderate amounts of acid or base can be quantitated by the combination of information from injection and sample peak areas;A new, low capacity, anion-exchange resin is developed which possesses a unique selectivity for sulfate and oxalate over bromide and nitrate. This low capacity resin makes it possible to separate dicarboxylic acids without interference from inorganic ions. This selectivity is shown to be caused by interaction between the resin matrix and large monovalent anions. This resin also makes it possible to use very short columns, which reduces the analysis time for many anions. Efficiency of this resin is shown to be quite good.</p>