I use Agilent 8890 gas chromatography (GC) coupled with a PAL Autosampler 10-uL Liquid Syringe and 7010B triple quadrupole mass spectrometer (QQQ MS), for the identification and quantification of PCBs 209 congeners in fish. Last year we analyzed our samples using multiple reaction monitoring (MRM) mode using internal standard method. This year we need to rebuild the calibration curve using the same method and same standard but we are facing multiple problems. We cannot get the high response for all the analytes. Agilent technician helped us in every ways to fix our instrument but I believe there is a problem of our understanding.
