Brockman A H, Shah N N, Orlando R
Department of Biochemistry and Molecular Biology, University of Georgia, Athens 30602-4712, USA.
J Mass Spectrom. 1998 Nov;33(11):1141-7. doi: 10.1002/(SICI)1096-9888(1998110)33:11<1141::AID-JMS732>3.0.CO;2-U.
Matrix-assisted laser desorption/ionization (MALDI) probe surfaces derivatized with octadecanethiol (C18) can be 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 C18 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 C18-derivatized probes to bind biopolymers in fixed amounts frees the analyst from the necessity 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.
用十八烷硫醇（C18）衍生化的基质辅助激光解吸/电离（MALDI）探针表面可作为疏水固相萃取装置，直接在探针表面分离生物聚合物并脱盐。使用定量MALDI，可以确定与C18表面结合的肽的大致量，从而计算表面密度。已确定在探针表面结合的肽量与浸泡溶液中分析物的浓度无关（从高至亚纳克/毫升浓度），而是取决于表面暴露于分析物的浸泡时间。C18衍生化探针以固定量结合生物聚合物的能力使分析人员无需通过多次步骤（如连续稀释或真空干燥）来调整分析物浓度。这种时间节省导致MALDI技术的整体效率提高。
