NPD Detector

[MarkRob]

I'm thinking about getting a used GC with NPD detector

my question is should I try and get one injector and two detectors for dual column confirmation?

is this helpful, necessary?

thanks in advance

[Schmitty]

Although significantly more expensive, we run dual injectors with dual columns and detectors. What type of analysis will you be performing?

[krickos]

Well.

I would say it depends on what the second detector is and what you typically run. I generally prefere having two detectors unless you have dedicated system. Increases flexibility and confirmation options.

If you buy a new system and add a FID/TCD/ECD the extra cost is not that much in my opinion.

[gpronger]

The question you need to ask yourself is the frequency of confirmations. If your samples will have a strong likelihood of needing confirmation, then two NPDs using dissimilar columns is worthwhile. If your samples won't likely have many hits then go with one NPD. I generally go with two detectors (the same) and two dissimilar columns to allow simultaneous confirmation.

Regarding whether to have a detector of a different type, the question is how much idle time the instrument will have and if you will need to be switching much in and out to go from one analysis to the next. My experience has generally been that so long as the instrument is fairly busy, it is better to have dedicated systems than attempting to switch back and forth repetitively. The best scenario for this option is if you have two inlets and two (different) detector AND the columns have similar temperature max's. If this is your case, then you can relatively easily go from one analysis to the next.