TRH Large wave like baseline causing problems

[seamoro]

We are having problems with our TRH GCFID. Our soil samples are ok but are waters samples have a large wave like base line covering the bands. this wave like baseline line distorts the whole chromtgram where as now we are using individual blanks to subtract individual band regions from 1 sample so its like bsaeline subtracting 4 times the same sample with four different blanks.We are also getting negative peaks too. The soil trh baseline pretty smooth and i believe its because we use DCM/acteone for the blank with soils where as we use DCM with water samples and it appears that DCM is giving the problems. What to do?

[seamoro]

to further explain.........when we run our DCM before our samples. We want to use the DCM blank to subtract the baseline from our samples but because the baselines goes up and down with these dips and troughs the blank base never matches the sample baseline. therefore the blank may overcompensate or undercompensate the baseline when subtracted from the sample!