title: Shell and small particles; evaluation of new column technology.
abstract: The performance of 5 cm long columns packed with shell particles was compared to totally porous sub-2 microm particles in gradient and isocratic elution separations of hormones (dienogest, finasteride, gestodene, levonorgestrel, estradiol, ethinylestradiol, noretistherone acetate, bicalutamide and tibolone). Peak capacities around 140-150 could be achieved in 25 min with the 5 cm long columns. The Ascentis Express column (packed with 2.7 microm shell particles) showed similar efficiency to sub-2 microm particles under gradient conditions. Applying isocratic separation, the column of 2.7 microm shell particles had a reduced plate height minimum of approximately h=1.6. It was much smaller than obtained with totally porous particles (h approximately = 2.8). The impedance time also proved more favorable with 2.7 microm shell particles than with totally porous particles. The influence of extra-column volume on column efficiency was investigated. The extra-column dispersion of the chromatographic system may cause a shift of the HETP curves.
authors.affiliation: Formulation Development, Gedeon Richter Plc, Gyömroi út 19-21, Budapest X., Hungary. fekete.szabolcs1@chello.hu
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Fekete
authors.forename: Jeno
authors.initials: J
authors.lastname: Fekete
authors.forename: Katalin
authors.initials: K
authors.lastname: Ganzler
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods; D017097:Electric Impedance; D006728:Hormones / Q000032:analysis; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D004364:Pharmaceutical Preparations / Q000032:analysis; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013256:Steroids / Q000032:analysis
chemical_list: D006728:Hormones; D004364:Pharmaceutical Preparations; D013256:Steroids; D012822:Silicon Dioxide