The retention times are calculated from the moment the sample is injected
in the chromatographic column (IT FLASH or GC INJECTION). In the chromatogram, this
corresponds to the first peak observed in time, which is generated by the
flash heating of the injection trap (IT) of SAM-GC. This time is 
669810836.82 s (sclk) for GC 2 chromatogram and 
669814459.46 s (sclk) for GC 1 chromatogram. The retention times are 
calculated by subtracting this time, to the times of the peaks maxima.
The original TCD chromatograms are available in the file noise.csv.

GC column 2 run

peak 0 ;  GC2 INJECTION ; 0
peak 1 ;   ; 412
peak 2 ;   ; 622
peak 3 ;  ; 1038
peak 4 ;  ; 1736

GC column 1 run

peak 5 ; GC1 INJECTION  ; 0
peak 6 ;   ; 542
peak 7 ;   ; 632
peak 8 ;   ; 825
peak 9 ;   ; 1713
peak 10 ;   ; 1902

The abundance given in the table (species.csv) corresponds to the area of the 
most abundant mass peak which are measurable for each peak. The unit is 
counts/sec/sec. There is no baseline correction for this fit.
These surfaces are proportional to the amount of the species
detected when a peak is eluted. When peaks are co-eluted (over of different
peaks), the peaks are fitted using a gaussian function. If the fit does not work, 
only one surface value is given, corresponding to the sum of the
abundances of the species contributing to the peak.