Simple automated generation of gradient elution conditions in sequential injection chromatography using monolithic column
Abstract
The paper deals with the concept of simple automated creation of gradient profile of the mobile phase for gradient-elution sequential injection chromatography (GE-SIC). The feasibility and merits of this concept are demonstrated on the separation and simultaneous assay of indomethacin as active principle and of its two degradation products (5-methoxy-2-methylindoleacetic acid and 4-chloro-benzoic acid) in a topical pharmaceutical formulation.
The GE-SIC separation was performed with a FIAlab (R) 3000 SIC set-up (USA) equipped with an Onyx (TM) Monolithic C18 (25 mm x 4.6 mm, Phenomenex (R)) column, a six-port selection valve, a 5-mL syringe pump and a fiber-optics UV CCD detector. Ketoprofen was used as an internal standard (IS).
The gradient elution was achieved by automated reproducible mixing of acetonitrile and aqueous 0.2% phosphoric acid in the holding coil of the SIC system.