Chromatography Forum

I have to run GC/FID for simple, routine analyses. Can I Nitrogen 99.995% as a gas carrier or a much cleaner Nitrogen is needed?

All depends what the impurities are. Ideally you should look to 99.999% or better for carrier gas. Commonest impurity in Nitrogen is likely to be Oxygen, very bad for your GC column but easily removed with an in line trap. With the Gas spec given you could have issues if the impurities were Hydrocarbons but again by adding the right trap you can clean the gas up to a much better spec. Impurity were say CO2 or Argon then its not likely to make any difference