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obviously tolerate a wide range of diverse analytical conditions. However, many of the MALDI/TOF-
MS in-line interfaces that have been developed have met with limited success for the reasons previously
mentioned. If off-line measurements are made, there is little or no restriction on the choice of mass
spectrometer, probe or ion source.

Source contamination with inorganic residues does not occur to anything like the same extent, and any
type of buffer can be used (including inorganic buffers) if so desired. In addition, the use of off-line
procedures allows the two instruments to be physically separated, and are therefore more convenient to
operate, and each instrument can be optimized without affecting the performance of the other.

Figure 13.15
The Capillary Interface and Fraction Collector

The details of the transport fraction collecting system has been described in a previous report, [14]. It
consists of a rotating disk on the heated surface of which is deposited the eluent from the
electrophoretic capillary. After deposition, the disk is placed in the TOF-MS and rotated such that each
spot is sequentially exposed to the laser beam. The device allows the electrical connections to be
established with the separating capillary by one of two procedures. Either a coaxial sheath flow is
employed through which the electrical connection is made or the outer surface of the capillary is coated
with a gold filled epoxy resin. Both arrangements allow