Otherwise, are you able to run the calibration standards with the split closed just to see if the detector could potentially be linear? Then, you could put the ECD to 300 or 330C.Īre you dosing your calibration tubes all at once and leaving them in the autosampler for analysis? Or are you spiking them and immediately desorbing? As much as the Gerstel sampler is sealed, you might try spiking and then immediately running to see if there is a difference.
If you did want to try running the detector hotter, you could cool the ECD and install a section of Siltek guard column into the detector and then connect your analytical column to this guard column via a glass pressfit connector. It's probably best to run the ECD hotter but the upper temperature limit of your analytical column isn't compatible with temperatures much greater than 240C. My chromatography is not as good, but it's more reliable.įeel free to skip over this CIS issue I don't want to drag anyone else into this craziness, haha.ĮDIT: If anyone does want to tackle the CIS issues, I suppose the CIS method information would be relevant (this is a separate method than the one I'm currently using and already described) The inlet just sits at 275C and the desorption flow runs right onto the column. They are very nice and helpful, but honestly did not know what was going on (neither did I). I have been in correspondence with Gerstel about this. A spike could be 33000 counts one run and 8000 the next. I could run the same spike multiple times and get very, very different responses. The peaks were completely separated, sharp, and symmetrical. I had (what looked to be) a pretty good CIS method.
The CIS is another can of worms entirely. The sample tubes in the actual study are sampled from a vapor source, but these tubes for the calibration are simply spiked on the head of the tube with 1uL of methanol with the appropriate concentrations of analytes, then room temperature nitrogen is run through for 3 min at 50mL/min. Is that abnormally low? I apologize for my inexperience with this, I have only been using MS detectors until now.
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