The use of an internal standard extends the linear range of the SALDI MS analyses
| Authors | |
|---|---|
| Year of publication | 2012 |
| Type | Article in Proceedings |
| Conference | CECE 2012 |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.ce-ce.org/cece2012/Proceedings%20CECE%202012%20Final+late%20abstracts_web.pdf |
| Field | Analytic chemistry |
| Keywords | SALDI MS; nanoparticles; internal standard |
| Description | Surface-assisted laser desorption/ionization mass spectrometry (SALDI MS) employing gold nanoparticles (Au NPs) has been presented as a useful method for the both qualitative and quantitative analysis of low molecular weight analytes. Besides the well-known benefit, such as the improvement in the analysis precision, the use of an internal standard was observed to extend the linear range of SALDI MS. Without the use of the internal standard, the linear range is presumably limited by the saturation of the Au NP surface where the desorption process takes place: at higher analyte concentration, an imperfect, multilayer assembly is formed leading to inefficient desorption and/or ionization and thus to reduced linearity and poor reproducibility. An internal standard can partially eliminate this limitation: as long as the Au NP surface is not fully saturated, the signal intensities of the analyte and the internal standard do not affect each other; with further increase of the analyte concentration, the signal intensity of the internal standard is gradually suppressed preserving the linearity the analyte/internal standard ratio. Although quantitative analyses using SALDI MS without any internal standard were presented, based on our findings the use of the internal standard for quantitative analysis is highly recommended. The limited Au NP surface as well as interfering components can have notable consequences in analyses of complex samples, especially if the nanoparticles are employed as extraction/concentration probes. |
| Related projects: |