THE DEVELOPMENT AND STUDY OF CHELATING SUBSTRATES FOR THE SEPARATION OF METAL IONS IN COMPLEX SAMPLE MATRICES

Abstract

The fabrication and study of high performance chelating substrates for the separation of trace metals using a single column under both isocratic and gradient elutions were investigated. Neutral polystyrene based resins from a variety of manufacturers including a hypercrosslinked resin (MN 200) were functionalised via impregnation with chelating dyestuffs or dynamically modified with small, low molecular weight organic molecules by physical adsorption and chemisorption processes respectively. Improvements in the impregnation of substrates were developed, based upon ultrasonic agitation, along with improvements in the detection of metal ions by the use of a noise reduction system, eluent clean-up procedures and large volume injections. The chelating substrates were characterised by studying their ability to retain metal cations (i.e. their capacity factors), column efficiency and separating power as well as their suitability for analytical applications. Other factors including ionic strength, pH, degree of crosslinking, column length and capacity were investigated to determine the separation capabilities of the substrates. Those substrates deemed to have the most suitable capabilities were employed for the determination of trace metals in a variety of complex sample matrices.