FormNo. 203-821-259 02/05-REV0
LECO is a registered trademark of LECO Corporation
6
Table 1 contains the information used to construct the new file from Resample and illustrates the
resulting file size reduction. It is important to note that the original file is completely intact and
could even be used again to construct a new filewith different Resample parameters.
Table1.
Resample parameters and reduced file size.
ResampleParameter
Old File
New File
Sample reduction rate
1
1
Beginning retention time (sec.)
60
1850
Ending retention time (sec.)
4810
3550
Beginningmass
35
35
Endingmass
450
250
File size (Mb)
377.9
70.4
For the previous example of Resample, it was not necessary to use the sample reduction rate
parameter, as the peak widths generated for GCxGC of the PIANOmixmandated the 100
spectra/second acquisition rate. During a GCxGC-TOFMS analysis for PBDEs though,
decabromodiphenyl ether (BDE 209), which is notoriously tough to chromatograph, showed very
broad peaks (slices) that were over-sampled at the 50 spectra/second rate that was appropriate for
other PBDEs (Figure 5).
BDE 47
Br
4
BDE 209
Br
10
Width
200ms
Width
2 s
Figure5.
Linear chromatograms showingmodulated peaks for BDEs 47 (tetrabromo) and 209
(decabromo). 50 spectra/second is an appropriate acquisition rate for the 200ms wide peaks of
BDE 47, but the rate is too fast for the broad peaks of BDE 209 (which results in a sensitivity
decrease).
