Chromatography Forum

Hi,

I want to dissolve vinyl chloride gas into DI water and measure it in GC hP6890-FID system. I purchased a 14 L gas cylinder which is 100ppm vinyl chloride in nitrogen and a gas regulator with syringe adapter in it. When I prepare the VC solution, I opened the gas cylinder valve and turn the knob in regulator to adjust flow. After 30seconds I insert my gastight syringe and take out 1mL gas and then inject to 20ml vial full with water through septum. But I couldn't find the peak for vinyl chloride for this solution, either with headspace or purge&trap method. Could anyone tell me any wrong operation in this process? Since VC is less soluble in water, how can I dissolve it fully in water and how long will it take to fully dissolve in water? Thanks very much!

You can purchase vinyl chloride as a solution in methanol. You take a portion of the solution and add it to water. It should be available from a number of sources. The first one I found is: http://www.restek.com/restek/prod/5800.asp

Catbear32,

Have you had any success in dissolving VC in water? I'm trying to determine VC by Headspace GCFID, Porapak Q column. Any help is much appreciated!

Eric

The procedure is in the old versions of 8260 ( https://www.epa.gov/sites/production/fi ... /8260b.pdf ) section 5.7
It has been deleted in the latest version because we felt that few people do it anymore. And it's so easy to buy it as a certified standard.

The procedure is in the old versions of 8260 ( https://www.epa.gov/sites/production/fi ... /8260b.pdf ) section 5.7
It has been deleted in the latest version because we felt that few people do it anymore. And it's so easy to buy it as a certified standard.

I have done VC bubbled into methanol in a volumetric flask on a balance before, bubble it and watch the weight increase until you get the desired concentration then bring to volume and you have a methanol standard you can dilute into water. Never tried to put VC directly into water before, seems it would be too difficult to get an exact concentration at such low levels.

Injecting the one ml of nitrogen VC standard into a 20ml vial of water would probably result in the VC being in the gas bubble at the top with little or no VC in the water itself.