Fig. 2.

HPLC chromatograms obtained for a-c low-range and d wide-range ssRNAs using a COSMOSIL RNA-RP1 column (2.0 mm I. D. x 100 mm; particle size, 5 μm). HPLC analysis was performed with a 400 mM HFIP-TEA buffer, b 100 mM TEAA, and c-d 100 mM TEAA-20 mM PB (pH 7.0) using a linear gradient from a 15% to 25%, b 10% to 25% (solvent B; methanol) and 5% to 20% (solvent B; acetonitrile), c 8.5% to 21% (solvent B; methanol) and 3.5% to 16% (solvent B; acetonitrile), and d 14% to 17% (solvent B; methanol) and 7% to 10% (solvent B; acetonitrile) with methanol or acetonitrile over 20 min at a flow rate 0.2 mL/min and a temperature of 65 °C. UV detection was performed at 260 nm