Optimization of a hydrophobic solid-phase extraction interface for matrix-assisted laser desorption/ionization

✍ Scribed by Brockman, Adam H.; Shah, Nina N.; Orlando, Ron

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 134 KB
• Volume: 33
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(1998110)33:11<1141::aid-jms732>3.0.co;2-u

✦ Synopsis

Matrix-assisted laser desorption/ionization (MALDI) probe surfaces derivatized with octadecanethiol can be (C 18 ) used as hydrophobic solid-phase extraction devices to isolate and desalt biopolymers directly on the probe surface. Using quantitative MALDI, it was possible to determine the approximate amount of peptide that bound to C 18 surfaces and thus to calculate a surface density. It was determined that the amount of peptide bound at the probe surface was independent of the analyte concentration in the immersion solution (from high-to sub-ng ml-1 concentrations), but rather was dependent on the immersion time of the surface as it was exposed to the analyte. The capacity of probes to bind biopolymers in Ðxed amounts frees the analyst from the necessity C 18 -derivatized for adjusting analyte concentration through multiple step procedures such as serial dilution or vacuum drying. This time savings result in an overall increase in the efficiency of the MALDI technique.