| | | Bond Elut® C8 • Base silica: 40 um or 120 um irregularly-shaped, acid-washed silica, 60 A mean pore size • Bonded functional group: octyl • Endcapped:yes • Typical carbon loading: 12.2% • Primary retention mechanism: moderately nonpolar • Typical sample types: water, aqueous biological samples | | Bond Elut® C18 | |
| | | • Base silica: 40 um or 120 um irregularly-shaped, acid-washed silica, 60 A mean pore size • Bonded functional group: trifunctional octadecyl • Endcapped: yes • Typical carbon loading: 17.4% • Primary retention mechanism: strongly nonpolar • Typical sample types: water, aqueous biological fluids | | |
| | | Bond Elut C8 sorbent C8 is very similar in property to C18, but is not as retentive for nonpolar compounds due to its shorter hydrocarbon professional chain. C8 is a good replacement for C18 when analytes are too strongly retained on C18 for effective elution. The potential of C8 for polar interactions with analytes is somewhat higher than for C18 because the shorter hydrocarbon chain does not professional mask the silica surface as effectively, but polar interactions are still not a significant property of C8. The C8 sorbent has been successfully utilized in the simultaneous extraction of fat- and water-soluble vitamins from human serum. For assistance selecting the best sorbent for your application, please see the Sorbent Selection Guide on pages 5-11, or visit www.varianinc.com and use our Applications Online Scanview database. | | Bond Elut C18 sorbent C18 is the most hydrophobic silica-based sorbent available. It is the most popular SPE sorbent because of its extreme retentive nature for nonpolar compounds. C18 is generally regarded as the least selective silica based sorbent, since it retains most organic analytes from aqueous matrices, often a benefit when the compounds of interest vary widely in structure. The potential for polar interactions between analytes and sorbent is less significant with C18 than with any other sorbent because of the predominant effect of the long hydrocarbon chain. When analyzing small to intermediate molecules, C18 can also be utilized for desalting aqueous matrices prior to ion exchange because salts pass through it unretained. For assistance selecting the best sorbent for your application, please see the Sorbent Selection Guide on pages 5-11, or visit www.varianinc.com and use our Applications Online Scanview database. | | |