High detection sensitivity achieved with cryogenic detectors in combination with matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry.
Cryogenic detectors directly measure the impact energy of any impinging particle independent of its velocity. Thus a very high, mass-independent, detection efficiency is expected from their application in TOF-MS. The cryogenic detector applied here is based on a superconducting phase-transition thermometer and was implemented in a dual reflector time-of-flight mass spectrometer (N-geometry). A dilution series using standard sample preparation procedures shows that the detection limit for insulin (Mr: 5,734) can be decreased by several orders of magnitude, down to 0.5 amol on the MALDI target. Detection limits for rhM-CSF beta (Mr: 49,032) and for polyclonal IgG (Mr: ca 150,000) in the high femtomole and low picomole range, respectively, were established.
Christ
P
P
Max Planck Institut für Physik, Föhringer Ring 6, 80805 München, Germany. christ@mppmu.mpg.de
Rutzinger
S
S
Seidel
W
W
Uchaikin
S
S
Prö
F
F
Koy
C
C
Glocker
M O
MO
D003080:Cold Temperature; D007074:Immunoglobulin G / Q000032:analysis / Q000737:chemistry; D007328:Insulin / Q000032:analysis / Q000737:chemistry; D016173:Macrophage Colony-Stimulating Factor / Q000032:analysis / Q000737:chemistry; D008970:Molecular Weight; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D007074:Immunoglobulin G; D007328:Insulin; D016173:Macrophage Colony-Stimulating Factor