Chromatography Forum

Dear all,
I am trying to separate Formaldehyde via an HP-5 MS (Agilent) column.
My GC-MS Model is Agilent 8890 and 5977b respectively.
N:B:- We don't have a headspace sampler.

My question is:-
1. Can i separate formaldehyde in this column? Or i need to follow the Derivatization of Formaldehyde?
2. What is the proper method for analyzing 40% formaldehyde solution with my above-mentioned system?

Thanks in advance.
Sincerely,
Tarek

One problem with Formaldehyde on MS is the mass in near that of Oxygen and Methanol and those will interfere with sensitivity but with such a concentrated solution that shouldn't be a problem.

With that column Formaldehyde will elute very early even with a starting oven temperature near 30C.

You can see here how early it elutes even on a similar phase designed specifically for volatile organic analysis.

https://www.restek.com/chromatogram/view/GC_AR1161

You should have a large peak even with a 10:1 split injection (liquid injection) with a concentration around 100ppm, so at 48% you will either need a very high split ratio or need to dilute the sample before injection.

What is your sample matrix?

2. What is the proper method for analyzing 40% formaldehyde solution with my above-mentioned system?

Not appropriate.

2. What is the proper method for analyzing 40% formaldehyde solution

Redox titration.

One problem with Formaldehyde on MS is the mass in near that of Oxygen and Methanol and those will interfere with sensitivity but with such a concentrated solution that shouldn't be a problem.

With that column, Formaldehyde will elute very early even with a starting oven temperature near 30C.

You can see here how early it elutes even on a similar phase designed specifically for volatile organic analysis.

https://www.restek.com/chromatogram/view/GC_AR1161

You should have a large peak even with a 10:1 split injection (liquid injection) with a concentration around 100ppm, so at 48% you will either need a very high split ratio or need to dilute the sample before injection.

What is your sample matrix?

The fixing agent in textile is the matrix. But, I am trying to run the 40% formaldehyde solution primarily. will it be ok?

The fixing agent in textile is the matrix. But, I am trying to run the 40% formaldehyde solution primarily. will it be ok?

I really don't fully understand, maybe English is not your first language.

If the formaldehyde is in the textile matrix, extract it with water and then assay the water for formaldehyde. Colorimetric assay of formaldehyde with acetyl acetone has been used for decades and is pretty sensitive.

One problem with Formaldehyde on MS is the mass in near that of Oxygen and Methanol and those will interfere with sensitivity but with such a concentrated solution that shouldn't be a problem.

With that column, Formaldehyde will elute very early even with a starting oven temperature near 30C.

You can see here how early it elutes even on a similar phase designed specifically for volatile organic analysis.

https://www.restek.com/chromatogram/view/GC_AR1161

You should have a large peak even with a 10:1 split injection (liquid injection) with a concentration around 100ppm, so at 48% you will either need a very high split ratio or need to dilute the sample before injection.

What is your sample matrix?

The fixing agent in textile is the matrix. But, I am trying to run the 40% formaldehyde solution primarily. will it be ok?

What is the fixing agent being used? Is it organic or water soluble solution?

Water injections are not the best thing to do on a Mass Spec. If you could redissolve or dilute into an organic solvent it may be better, but with either the water or other organic solvent you will probably have the formaldehyde eluting before the solvent peak which could cause problems with the filaments on the MS. You may want to look into a different sample preparation method like Static Headspace or Solid Phase Micro Extraction (SPME) for this type of analysis.

If you derivatize then you will be making the formaldehyde a heavier molecule which will elute later and solve many of the problems found with trying to directly measure it. Also as above, it the concentration is 40%, you will probably have just a accurate or maybe even more accurate results by titration instead of having the errors introduced when doing dilutions, extractions, or derivatizations.

I have experience with this method and the best and easiest way is just UV-VIS

Hello Yeasin,

Can I contact or email you about this subject?

Best regards,
George