Enhanced capabilities of separation in Sequential Injection Chromatography – Fused-core particle column and its comparison with narrow-bore monolithic column

In the Sequential Injection Chromatography (SIC) only monolithic columns for chromatographic separations have been used so far. This article presents the first use of fused-core particle packed column in an attempt to extend of the chromatographic capabilities of the SIC system. A new fused-core particle column (2.7 μm) Ascentis® Express C18 (Supelco™ Analytical) 30 mm × 4.6 mm brings high separation efficiency within flow rates and pressures comparable to monolithic column Chromolith® Performance RP-18e 100-3 (Merck®) 100 mm × 3 mm. Both columns matches the conditions of the commercially produced SIC system – SIChrom™ (8-port high-pressure selection valve and medium-pressure Sapphire™ syringe pump with 4 mL reservoir – maximal work pressure 1000 PSI) (FIAlab®, USA). The system was tested by the separation of four estrogens with similar structure and an internal standard – ethylparaben. The mobile phase composed of acetonitrile/water (40/60 (v/v)) was pumped isocratic at flow rate 0.48 mL min−1. Spectrophotometric detection was performed at wavelength of 225 nm and injected volume of sample solutions was 10 μL. The chromatographic characteristics of both columns were compared. Obtained results and conclusions have shown that both fused-core particle column and longer narrow shaped monolithic column bring benefits into the SIC method.