Preservatives

[Rick Jagielski]

Hi all,

I have an interesting problem.

For preservatives in cosmetics there are two substances that I need to deal with, diazolidinyl urea and sodium hydroxymethylglycenate.

These two act as formaldehyde releasers in creams and lotions. the problem I am faced with is how to go about analyzing for these substances in a cream matrix.

These substances break down into formaldehyde which can be derivtized and analyzed by HPLC. (lots of stuff from NIOSH here) However I am not sure how to go about dealing with all of the species that the preservative is in. diazolidinyl urea will have decomposition states representing a loss from zero to four moles of formaldehyde per mole of starting material.

How would you go about setting up an extraction scheme?
What column or method parameters would you suggest?

Thanks

Rick

[Mark Tracy]

Years ago, I had a customer doing these type of formaldehyde-releasing compounds. They were analyzed by normal-phase HPLC on a diol column and the mobile phase was mostly acetonitrile. I think they were using post-column reaction for the detection.

I have found creams can be partitioned between 70% ethanol and heptane with good results.

[Rick Jagielski]

Mark,

Do you recall which species they were quantifying? Were they testing to determine how much of the starting species was there, or were they doing a hydrolisis step to break it down to formaldehyde/formic before quantification?

I did some net research and came up with this goodie...

http://europa.eu.int/comm/health/ph_ris ... 187_en.pdf

This indicates to me that I would be wasting my time to try to quantify the starting material using their methodology.

Thanks
Rick

[Mark Tracy]

They were separating the various formaldehyde-releasing complexes in their initial forms. I don't recall the exact ones. The hydrolysis and color-reaction was post-column (Hantzsch reaction, I think).