HPLC of basic drugs using non-aqueous ionic eluents: evaluation of a 3 mum strong cation-exchange material.
HPLC columns packed with 3 microm particle size HPLC Technology Techsphere SCX (propylsulfonic acid-modified) silica offer considerable advantages over 5 microm SCX packings in the analysis of basic drugs using 100% methanol eluents containing an ionic modifier such as ammonium perchlorate. The basic drugs studied included clozapine and norclozapine, olanzapine, quinine and quinidine, and amitriptyline, nortriptyline, imipramine and desipramine. The 3 microm column was not only more efficient for a given column length compared with 5 microm materials, but also elution times were less, a phenomenon observed in reversed-phase systems. The high efficiencies and excellent peak shapes obtained with the 3 microm SCX-modified packing together with the relatively low back-pressures attained show that such materials deserve serious consideration by laboratories involved in the analysis of basic drugs. Manufacturers should offer such packings as a matter of routine. Alternative ionic modifiers such as ammonium acetate are available for use with mass spectrometric detection if required.
Morgan
Phillip E
PE
Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, UK. phillip.morgan@kch.nhs.uk
Manwaring
Victoria
V
Flanagan
Robert J
RJ
D017738:Alkanesulfonic Acids / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D010472:Perchlorates / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000032:analysis*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
D017738:Alkanesulfonic Acids; D002412:Cations; D010472:Perchlorates; D004364:Pharmaceutical Preparations; D000644:Quaternary Ammonium Compounds; C068559:propylsulfonic acid; D012822:Silicon Dioxide; C053506:ammonium perchlorate