Need help with GC-ECD

[Mattia]

Hello everyone,

I have some problems with an ECC-GC system. I should use the system for the quantification of chlorinated solvents in water. I use a protocol, which included the thermal event of the system. 

 

My problems:

 

if I go from SPLIT to SPLITLESS, I have a total loss in signal with a flat line (no picks). If I increase the SPLIT, all the picks appear in chromatogram. WHY??

 

if I try to set a calibration curve, the system gives me an inverted curve: the highest concentration compound responds less than the low concentration one. All these compounds are perfectly linear. (I use fresh mix compounds made at the moment, which include 5 compounds).

All compounds have curves with R2 0.99, but are in fact "flipped"

 

Any tips??