Active content of H2S

[praveenpaliwal]

Hi experts,

I am analyzing H2S gas on GC. I used three columns DB-624, SP-2331 and ULBON Hr-1 I got good peak of H2S. But the task is not complete. I need standard of H2S. Now the problem is that How can I get the standard to draw calibration curve. H2S is available as a standard pack yes it is available in ALdrich but in case of active content it required the amount of standard n here I can not measure the weighement of H2S.
Any body tell me that is H2S is available in the solution form along with some organic solvent like MDC, EDC or Toluene. (i.e X% of H2S in organic solvent) so that I can use this solvent and find out the calibration curve.
I need view of all of u experts

Best regards

Praveen

[chromatographer1]

I have never heard of H2S being available in solution. This volatile gas would not be stable in solution, especially after any container would be unsealed.

I have only seen it available as a pure gas or as part of a gas mixture from a cylinder.

Good hunting.

Rod

[praveenpaliwal]

Ok Rod,

Then please tell me any mixture which will produce the certain amount or mole H2S gas so that we can prepare the standard???
Best regards

Praveen

[chromatographer1]

You can buy calibration mixes premade or order custom mixes which come in cylinders. Your gas supplier can direct you to a good source of these products.

Good luck,

Rod

[AICMM]

praveenpaliwal,

You have three choices here. One, as Rod noted, you buy a gas standard at the high end of your concentration range and you dilute with some other gas based on flow rates to build yourself a curve. (Of course this is gas based.) Two, buy a piston with the H2S dissolved in a solvent and you use a liquid valve to inject the the solvent. This method leaves you very little flexibility for dilutions other than multiple pistons at different concentrations. Also, pistons are operated at high pressures in order to keep the H2S dissolved in the solvent; can your instrument handle this? Three, you use a permeation device and you change your dilution ratio of flowing gas (or temperature but that is not usually recommended) to vary the concentration.

I get the impression that none of these will answer your question?

Best regards,

AICMM

[praveenpaliwal]

Thanks 4 ur reply. H2s is generated in one of our reaction we strip this gas in toluene and we got the purity of H2s in toluene solution by iodometrically. finally we plot a calibration curve of H2S gas. I also done lot of search but regarding to standard solution of H2S I do not found any standard.
Any way thanks fro ur suggestion

regards

Praveen