Procedure Ion chromatography

chamber (left) contains high salt concentration. stirred chamber (right) contains low salt concentration. gradual stirring causes formation of salt gradient salt travel high low concentrations.

comparatively simple devices used apply counterions of increasing gradient chromatography column. counterions such copper(ii) chosen separating peptides , amino acids through complex formation.

a simple device can used create salt gradient. elution buffer consistently being drawn chamber mixing chamber, thereby altering buffer concentration. generally, buffer placed chamber of high initial concentration, whereas buffer placed stirred chamber of low concentration. high concentration buffer left chamber mixed , drawn column, buffer concentration of stirred column gradually increase. altering shapes of stirred chamber, of limit buffer, allows production of concave, linear, or convex gradients of counterion.

a multitude of different mediums used stationary phase. among common immobilized charged groups used trimethylaminoethyl (tam), triethylaminoethyl (teae), diethyl-2-hydroxypropylaminoethyl (qae), aminoethyl (ae), diethylaminoethyl (deae), sulpho (s), sulphomethyl (sm), sulphopropyl (sp), carboxy (c), , carboxymethyl (cm).

successful packing of column important aspect of ion chromatography. stability , efficiency of final column depends on packing methods, solvent used, , factors affect mechanical properties of column. in contrast inefficient dry- packing methods, wet slurry packing, in particles suspended in appropriate solvent delivered column under pressure, shows significant improvement. 3 different approaches can employed in performing wet slurry packing: balanced density method (solvent’s density of porous silica particles), high viscosity method (a solvent of high viscosity used), , low viscosity slurry method (performed low viscosity solvents).

polystyrene used medium ion- exchange. made polymerization of styrene use of divinylbenzene , benzoyl peroxide. such exchangers form hydrophobic interactions proteins can irreversible. due property, polystyrene ion exchangers not suitable protein separation. used on other hand separation of small molecules in amino acid separation , removal of salt water. polystyrene ion exchangers large pores can used separation of protein must coated hydrophillic substance.

cellulose based medium can used separation of large molecules contain large pores. protein binding in medium high , has low hydrophobic character. deae anion exchange matrix produced positive side group of diethylaminoethyl bound cellulose or sephadex.

agarose gel based medium contain large pores substitution ability lower in comparison dextrans. ability of medium swell in liquid based on cross-linking of these substances, ph , ion concentrations of buffers used.

incorporation of high temperature , pressure allows significant increase in efficiency of ion chromatography, along decrease in time. temperature has influence of selectivity due effects on retention properties. retention factor (k = (tr − tm)/(tm − text)) increases temperature small ions, , opposite trend observed larger ions.

despite ion selectivity in different mediums, further research being done perform ion exchange chromatography through range of 40–175 c.

an appropriate solvent can chosen based on observations of how column particles behave in solvent. using optical microscope, 1 can distinguish desirable dispersed state of slurry aggregated particles.