Surface Morphology Variations in MALDI-TOF-Mass Spectrometry Samples Prepared by Various Techniques Examined by Scanning Electron Microscopy
William R. Blair, Charles M. Guttman, A A. Guiseppetti
Continuing interest at NIST (National Institute of Standards and Technology) in producing MALDI (Matrix Assisted Laser Desorption/Ionization) analyses with a mimimum of sample to sample signal variation has led to the comparison of hand spotting, spin coating and electrospray sample preparation techniques. The spin coating technique was abandoned after electrospray demonstrated a clear superiority in producing samples with reduced signal intensity variations. Samples were prepared in a variety of matrices, both by hand spotting and electrospray techniques. For selected polymer/matrix combinations, using electrospray instead of hand spotting for sample preparation reduced signal intensity variations from 40% to nearly that of the variation measured in the output of the MALDI laser, approximately 4 % to 5%. For SEM (Scanning Electron Microscopy), samples were given a light gold coating and examined in a JEOL model 5300 micriscope. MALDI analyses were performed on a Bruker Reflex II MALDI-TOF Mass Spectrometer. For most samples, significant differences were seen in matrix crystal size and shape depending on sample preparation technique. The more consistant signal intensities acheived with electrosprayed samples appears to derive in part from the more uniform surface features that promote more efficient polymer ionization by the laser pulse.
Proceedings of the 48th ASMS Conference on Mass Spectrometry and Allied Topics
June 11-15, 2000
Long Beach, CA
ASMS Conference on Mass Spectrometry and Allied Topics
, Guttman, C.
and Guiseppetti, A.
Surface Morphology Variations in MALDI-TOF-Mass Spectrometry Samples Prepared by Various Techniques Examined by Scanning Electron Microscopy, Proceedings of the 48th ASMS Conference on Mass Spectrometry and Allied Topics, Long Beach, CA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851759
(Accessed December 4, 2023)