Chromatography Forum

Hi. I have a problem.

With this method:

Colonna: 0.1% AT1000 su Carbograph 2 80/100 mesh in Colonna in vetro l: 2m id: 2mm; od: ¼’ configurazione A per GC Agilent 6890/7890
Carrier: Azoto a 30ml/minuto costanti
Temperatura Iniettore: 200°C
Temperatura FID: 200°C
Temperatura Colonna: 70°C isoterma
Volume d’iniezione: 2µl

Solvent for dilution Is Water.

With this system Life of column Is very very short (3 or 4 sequence analytical)

Any ideas?

Thanks

Is headspace an option for you?
Sounds like you're testing for VOCs in something nasty. Switching sampling to HS or going from a packed to a PLOT column may help, if you're "allowed" to.

etaxene,

DR is right. Headspace would be a good idea if you can get away with it.

Water is a terrible dilution solvent due to polarity and expansion volume. That said, that packed column should be able to handle it.... with some important comments. I would advise not packed to the ends, leaving some room or a lot of room at the end of the column for water expansion. 2 uL water makes at least 2 mL of gas phase and you have to hold that somewhere. Also, at 30 mL/min, 2 mL of volume is going to yield broader peaks....

Likewise, I would recommend a decent sized glass wool plug at the front that you can remove and replace if you sample is ugly. May be that the front of the columns is getting junked up.

Best regards,

AICMM