Interference No. 104,745
A solution containing the analyte material enters the ES (electrospray) chamber 1 through a
stainless steel hypodermic needle 2 maintained at a few kilovolts relative to the walls and end-
plate 3 (col. 9, ll. 31-35). The aperture leading into the vacuum system 4 can be in the form of a
simple orifice or nozzle or, as shown in the figure, a capillary 5 of dielectric material (id. at ll.
53-61).
The respective advantages of the prior-art MALDI and ESI systems are described as
follows in Laiko's involved patent specification:
The advantages of MALDI include simplicity of probe preparation, stability and
high tolerance to sample contamination. One of the major advantages of ESI is
the atmospheric pressure character of ionization (external with respect to a mass
spectrometer), which enables a direct on-line interface with other analytical
separation techniques, such as HPLC, CZE, and IMS. An Atmospheric Pressure
Interface (API) is used to transfer ions from an atmospheric pressure ion source,
such as an ESI, to a vacuum of a mass spectrometer.
Laiko Specification, col. 1, ll. 57-67. The invention at issue in this interference obtains the
advantages of both of these techniques by using
MALDI to generate analyte ions at atmospheric
pressure, referred to as AP-MALDI.
Laiko's Figure 1 (described at col. 4, l. 26 to
col. 5, l. 2) shows one of Laiko's disclosed
embodiments of an AP-MALDI apparatus 10:
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Last modified: November 3, 2007