Chromatography Forum

Hello to all, i m confusing about the carrier gas purification grades. recently i m using 99.999% pure hydrogen gas as carrier in ABB 3100 VISTA GC. gc grade hydrogen is suggested in its documents. Now can i use 99.996% here and if i do so what problems can i face?
if anybody have carrier gas grades table ,pl send me i should b thankful to him.

The answer depends upon the impurities that are in the hydrogen and the sample you are injecting, as well as the type of detector you are using.

Since I know none of the above that is all the answer I can give you.

best wishes,

Rod

Whatever grade of gas you have in the cylinders, for carrier gas you need gas scrubber cartridges immediately upstream of the GC to protect your columns from the effects of oxygen and moisture. 99.999% pure gives a reasonable balance between the cost of gas and the lifetime of scrubbers.

Peter

You need to talk to your vendor and learn WHY you require such high purity gas. Your gas supplier will be able to tell you what impurities the gas they sell you contains. Then you should be able to determine what effect that will have on your Vista process GC and if you should install traps. Many times especially in a process GC the installation of traps may only increase the amount of impurity gases due to leaks and permeation of gases into your gas supply.

They will also tell you if your gas supplier's gas is adequate for your application and hardware.

best wishes,

Rod

thanks dears 4 quick reply. its ABB 3100 VISTA WITH TCD. I know high purity carrier gas is good in result and my vender also suggest gc grade. And analyzer is running good with it. but the problem is that this purity is tomuch costly and my firm is insisting to use 99.996.but i dont think so and secondly i personaly want to know ful information about gas purity grades becoz i stil dont know that 99.999 is it gc grade?

thanks once again chromatographer and peter.

Your gas vendor should be happy to explain the different grades of gas.

See the web sites of AIRGAS; Air Liquide;

You are asking for too much information to be given in a forum context as this.

Good luck in finding all the information you are seeking.

Rod

thanks dear, u understand my problem and answered correctly. now i can search needed information on indicated sites. actualy searching gas grades is dificult becoz diferant company have diferant standards. and i cant afford any mistake becoz i love my anlyzer.

I always go for 99.9999% purity. Depending on what the data is for, do you want to risk ghost peaks or lousy baseline?