Instrument & Materials
4.1.3.
The instrument features unusually simple construction, consisting of a single pump and single valve. The software allows all parameters of separation protocol and data collection to be controlled without reconfiguration of instrument hardware. A high precision, stepper motor driven syringe pump allows precise liquid metering at forward and reversed flow with pressures
up to 500 psi, and flow rates 0.006 to 9mL/min.
SIC uses an external column mounted in line between the multiposition valve and external detector, which is either a UV-Vis spectrophotometer or a PMT based fluorescence detector.
Column materials compatible with 500 psi operation fall into two categories: monolithic columns and fused core particle columns. Monoliths are a novel type of HPLC columns manufactured by Phenomenex and Merck. In contrast to conventional HPLC columns, the sol-gel monoliths are formed as a single piece of porous silica, having a higher porosity than conventional columns. Monoliths that use reversed-phase are most popular and have found many applications in separation of pharmaceuticals, proteins, oligonucleotides, organic acids and enantiomeric compounds.
Fused core particle columns are available from Agilent, Phenomenex and Supelco. The stationary phase is made of superficially porous silica solid core particles (solid core made of fused silica, the core being impenetrable by analytes while the surface is populated by functional groups such as C-18, RP-Amide, Phenyl-Hexyl, HILIC, F5, ES-Cyano).
