The Relationship between Crystal Condition and Mass Resolving Power, Mass Accuracy
The JMS-S3000 SpiralTOF™ has a unique 17 m flight path that offers the highest resolution MALDI-TOF MS system currently available. With an extended flight distance, the SpiralTOF reduces topographic effect of matrix crystal to a minimum and achieves highly reproducible mass resolving power and high mass accuracy with external mass calibration. In this work, we demonstrate the measurement of a polymer standard with 4 types of matrices that are typically used for MALDI polymer measurement by using the JEOL SpiralTOF system. Additionally, we looked at the crystal condition using the JEOL JSM-7600F thermal field emission scanning electron microscope (FE-SEM).
Sample information and preparation conditions are shown in Table 1. PEG1500 was dissolved in water at a concentration of 10 mg/mL. Each matrix was dissolved in THF at a concentration of 10 mg/mL. NaI used as the cationization agent was dissolved in THF at a concentration of 1 mg/mL. Next, the PEG1500, NaI and matrix solutions were mixed together 1:1:2 (1:1:4 for DIT) by volume. Afterwards, 0.75 μL of this mixture was placed on the hairline finish stainless steel plate (MTP format, 384 spots for samples and 96 spot for calibrant). Finally, the dried sample was measured using the JMS-S3000 SpiralTOF MS system. We also obtained SEM images for each crystal condition with the JSM-7600F.