A phase less hydrophobic than C18. Provides less retention of both polar and non-polar compounds than C18. Use a mobile phase containing 5% less organic modifier for the C8 column than C18. Polar compounds are, relatively, more strongly retained on C8 than C18 columns.. Parameter: =70 °C temp. range. L × I.D.: 15 cm × 4.6 mm. Surface Coverage: Surface coverage 3.2 µmol/m2. . . Sigma-Aldrich 58983 SUPELCOSIL LC-8 HPLC Column, 3 µm Particle Size, 4.6mm ID, 15cm Length. Country of Origin : United States. Part Number : 1200D05EA. Pack of : 1.