Separation of transition metals on a poly-iminodiacetic acid grafted polymeric resin column with post-column reaction detection utilising a paired emitter-detector diode system

J Chromatogr A. 2008 Dec 5;1213(1):31-6. doi: 10.1016/j.chroma.2008.08.049. Epub 2008 Aug 19.

Abstract

The selectivity, retention and separation of transition metals on a short (2 mm x 50 mm) column packed with a poly-iminodiacetic acid functionalised polymer 10 microm resin (Dionex ProPac IMAC-10) are presented. This stationary phase, typically used for the separation of proteins, is composed of long chain poly-iminodiacetic acid groups grafted to a hydrophilic layer surrounding a 10 microm polymeric bead. Through the use of a combination of a multi-step pH and picolinic acid gradient, the separation of magnesium, iron, cobalt, cadmium, zinc, lead and copper was possible, followed by post-column reaction with 4-(2-pyridylazo) resorcinol (PAR) and absorbance detection at 510 nm using a novel and inexpensive optical detector, comprised of two light emitting diodes with one acting as a light source and the other as a detector. Column efficiency for selective transition metals was in excess of N=10,000, with the baseline separation of seven metal cations in <3 min possible under optimised conditions. Detection limits of between 5 and 81 microg/L were possible based upon a 50 microL injection volume.

MeSH terms

  • Chromatography, Affinity / instrumentation*
  • Chromatography, Affinity / methods
  • Imino Acids / chemistry*
  • Osmolar Concentration
  • Polymers / chemistry*
  • Resorcinols / chemistry
  • Temperature
  • Transition Elements / analysis*

Substances

  • Imino Acids
  • Polymers
  • Resorcinols
  • Transition Elements
  • 4-(2-pyridylazo)resorcinol
  • iminodiacetic acid