Hi Linda,

the standard method is the sodium sulfite method. Add an excess of sodium sulfite solution to the formaldehyde solution, then titrate with sulphuric acid and phenolphtaleine. The following reaction applies: 

CH2O + Na2SO3 + H2O → NaOH + Na[H2CSO4]

Refer to Walker for details:

Walker, J. F.; Formaldehyde;  ACS Monograph Series, 1964

Hope that helps.

Regards,

Oliver

Hi Oliver!

Thanks for your fast reply. I will look into this in practice in a few days. The reference will be of good help!

Best,

Linda

Dear Mss Önnby, I know that you would like a method for formalfehyde determination by titration. Mr. Steinhof already answered your question. However, I found this alternative method using spectrophotometry: Sensitive Spectrophotometric Abbas Afkhami and Mostafa Rezaei, Determination of Formaldehyde by Inhibition of the Malachite Green–Sulfite Reaction, Microchemical Journal 63, 243–249 (1999). Maybe this method can be inetereting for you. On the other hand, I have the book: Walker, J. F.; Formaldehyde. If you want, I can send for you. Kind regards.

Dear Mr Bastos Fernandes,

Thank you for your kind reply. If you have the Walker reference, I would be very happy to receive it from you. I will also look into the recommended reference from Afkhami and Rezaei. typically, I would like to confirm my stock solution which is why titration is preferred in this case.

Best regards

Linda ([email protected])

The best way for determining  formaldehyde is by using colorimetric determination using Florescence/UV-vis spectroscopy. You need to do standardization first (using titration as mentioned by Oliver which is available in Walker, Formaldehyde book) and using known formaldehyde concentration solutions that you prepared from your standard formaldehyde solution, you need to make your calibration curve using Florescence/UV-vis spectroscopy.

In order to detect formaldehyde with spectroscopy method, you need to react your formaldehyde solution with acetylacetone reagent, in this reaction each mole of formaldehyde will turn into a compound which has double bond and can be detected with spectroscopy methods. you can review this method in the following pubs:

Nash, T. 1953. The colorimetric estimation of formaldehyde by means of the Hantzsch reaction. Biochem J 55: 416-421.

Belman, S. 1963. The fluorimetric determination of formaldehyde. Anal Chim Acta 29: 120-126

Walker, J.F. 1975. Formaldehyde: Krieger Publishing Co., Huntington, N.Y.

Dear Mss Önnby,

I use hydroxylamine method for determining formaldehyde in my researches

The oximation reaction is carried out with hydroxylamine HCl which is very stable.

Each mole of oxime formed results in the formation of one mole of HCl which can be titrated with standard alkali to give a measure of the carbonyl in the sample.

Hi, mine is not to answer, but this thread is helpful to me because I am interested on detecting formalin on fish sold in markets. This is my first attempt, and I have no idea  how to do it. I checked on methods here (online) and I saw availability of test kit. Is the use of a test kit for formalin on fish could give reliable results? which method could be best for detecting formalin in fish? Thank you.

Does anyone know of a simple method for determination of formaldehyde in milk and milk products using titration or any other method?

Thanks!

How to calculate the titration test according to BP?