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GC and Helium shortage

Question asked by srstrangis on Nov 1, 2018
Latest reply on Nov 19, 2018 by srstrangis

Hi,

 

we are currently unable to get Helium. We'll run our Helium gas inventory in a few weeks. Between other applications for our facility, it is used as a carrier gas on our GCs for solvent analysis (validated method). I'm copying our method below. Would it be best to use N2 or H2? How do I calculate the equivalent flow. Any other option?

Thanks in advance.

 

1.1         Injector

Mode: splitless

Temperature: 250 oC

Carrier gas: Helium

1.2         Column

Type: fused silica capillary

Model:  DB-200 (J&W p/n 122-2033),

Nominal Length: 30m

Nominal diameter: 0.25mm

Nominal film thickness: 0.5 µm

Mode: constant pressure, 15 psi.

Nominal initial flow: 1.4 mL/min.

1.3         Detector

Type: FID

Temperature: 300oC

Hydrogen flow: 40 mL/min

Air flow: 350 mL/min

Mode: constant makeup flow

Makeup gas: Nitrogen (30 mL/min)

1.4         Temperature profile

Initial temperature: 40oC for 2 minutes

Ramp:  increased from 40oC to 130oC at a rate of 20oC/min

Ramp time: 4.5 minutes

Post temperature:  maintained at 130oC for 5.5 minutes.

  Total run time:  12 minutes

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