Sample preparation and analysis for atmospheric pressure matrix assisted laser desorption ionization time of flight mass spectrometry (AP- MALDI-TOF-MS) was investigated. By investigating the effects that sample preparation has upon MALDI signal, better analysis can be carried out. The influence of sample deposition was studied by not only observing the signal intensity produced but also by quantitation. Isotope dilution mass spectrometry (IDMS) was used for the quantitation of three different analytes. The results indicated that not only was signal greatly affected by sample deposition but the effect on quantitation error was also statistically significant among the three different sample deposition techniques that were evaluated.
Components of sample preparation solution were studied using polyethylene glycol (PEG) and polystryrene (PS) of different weights. This study altered the amounts of matrix, analyte and cationizing agent that were used to make up each sample. Not only did the sample signal intensity greatly vary which had statistical significance but a shifting of the polymer sample peaks was also observed. This confirms that sample preparation is of extreme importance for MALDI analysis.
Carpet fibers, glutathione and cell wall extracts from the bacteria Staphylococcus Epidermidis were also studied by AP- MADLI-TOF-MS. These analytes were carefully studied to provide an accurate characterization of each. The diversity of the analytes studied highlights the incredible capabilities that MADLI possesses being able to analyze a range of analytes. Though the samples were diverse each one was able to be completely and comprehensively analyzed using AP-MALDI-TOF-MS
