title: Improved resolution in the detection of oligonucleotides up to 60-mers in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using pulsed-delayed extraction with a simple high voltage transistor switch.
abstract: Pulsed-delayed extraction using a simple high voltage transistor switch together with various sample purification approaches were used to enhance the resolution in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) of oligonucleotides up to 60 bases long. This switch can provide a 0-3 kV voltage pulse with a 75 ns fall time. A resolution of 500-900 was typically observed for samples from 5-mers to 60-mers using pulsed-delayed extraction (PDE) with the switch described herein. The resolution deteriorated to < 100 for oligonucleotides of > or = 65-mers. With the TOF acceleration region configuration used in this work, the resolution was found not to vary significantly over a delay range of 2-5 mus. As the DNA size increased to over 35-mer, HPLC purification was required to retain the enhancement in resolution provided by PDE MALDI-MS.
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor 48109-1055, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhu
authors.forename: L
authors.initials: L
authors.lastname: He
authors.forename: J R
authors.initials: JR
authors.lastname: Srinivasan
authors.forename: D M
authors.initials: DM
authors.lastname: Lubman
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000032:analysis; D009841:Oligonucleotides / Q000032:analysis* / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation*; D014173:Transistors, Electronic
chemical_list: D009841:Oligonucleotides; D004247:DNA