... Borges and Pinto [26] showed ... a 250 mm × 2.0 mm id column packed with 5 μm Kromasil C18 stationary phase (Interchim) protected by a 10 mm × 2.0 mm C18 precolumn (Interchim) and heated to 25 °C. The flow rate was set at 150 μL/min and the injected volume was 20 ...