Abstrait

Retention behavior of selected basic, acidic and neutral analytes on three different chromatographic stationary phases in presence of chaotropicmobile phase additives

Hisham Hashem, MohamedAl Bratty, Thomas Jira

In this study the effect of type and concentration of two chaotropic counter anions namely perchlorate and dihydrogen phosphate in mobile phase on retention behavior of three basic compounds (tricyclic neuroleptics), one acidic compound (acetyl salicylic acid) along with one neutral compound (triamcinolone) was studied. The effect of change of concentration of the two chaotropic counter anions and the role of organic modifier type (methanol and acetonitrile)were considered.All these parameterswere studied for three different RP-columns (calixarene modified silica gel, monolithic and conventional RP-columns). The results indicate that all studied factors affected the chromatographic behavior of the studied compounds. The type and concentration of chaotropic counter anions have clear effect on the basic compounds retention while the retention of neutral and acidic compounds did not clearly change. The type of the used stationary phase was found to play an important role in retention behavior of the studied basic compounds.