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XCMS / Two-Dimensional RT Alignment
I'm interested in analysing some data from a Shimadzu GC/GC-MS (i.e. two dimensional of gas chromatography) with XCMS. As far as I can tell, 2D alignment is not something currently covered by XCMS, but it doesn't seem to be a million miles beyond current capability (although far from a simple tweak!). I wondered if anyone had any experience in approaching this issue.
The raw data (both vendor binary and when converted to open formats, e.g. mzXML) is stored as one-dimensional, i.e.:
Code: [Select]
Second Dimension GC -->becomes
First Dimension GC 1 2 3 4 5 6
| 7 8 9 10 11 12
V 13 14 15 16 17 18
Code: [Select]
<scan num="1"in the mzXML.
[other spectrum metadata]>
[spectrum]
</scan>
<scan num="2"
[other spectrum metadata]>
[spectrum]
</scan>
...
<scan num="18"
[other spectrum metadata]>
[spectrum]
</scan>
The dataspace is therefore comprised of the scan list and a parameter for the number of scans in each second dimension elution.
Best wishes, and thanks in advance for any advice!
Phil