Chromatography Forum

I'm looking for an IC or HPLC method for determination of gluteraldehyde. Could someone suggest a column and separation?

I'm in a small organization with limited access to journal articles.

Thanks,
Brian

I'd recommend reacting your glutaraldehyde with dinitrophenylhydrazine (DNPH) under acidic conditions (HCl will do) and developing a separation on a reversed phase column with UV detection at about 360 nm. I used such an assay to monitor acetone in our production plant's effluent for a while and it worked quite well. It was simple, fast, specific, reasonably sensitive (low ppm levels were easily measured), and robust.

I'd expect it to work the same for glutaraldehyde and Sigma even sells a DNPH-glutaraldehyde standard. I wouldn't bother, though - just make a series of stds and treat them the same as your sample with DNPH. It's cheap and you don't use much. If you need more information, feel free to drop me an email.

A Google search will reveal plenty of methods, many with free details, eg
http://www.osha.gov/dts/sltc/methods/or ... rg064.html
Most column manufacturers will have DNPH method applications freely available with detailed methods.

I've used a C8 column with perchloric acid, rather than the phosphoric acid suggested in the OSHA doc. The perchloric has faster kinetics, and works well at a lower concentration. They suggest a CN column, but C8 worked well for me, depends on potential interferences.

It's very easy, and there is a lot of detailed information available that a Google search using glutaraldehyde or carbonyl with DNPH and HPLC should reveal.

Bruce Hamilton

derivitizing aldehydes with DNPH works extremley well. I have devloped an assay for formaldehyde, so it should work with gluteraldehyde no problem.

Mobile phase is 55% water 45% ACN, 250 x 4.6mm C18 column (5um particle size). Flow rate 1 mL/min, Det at 360 nm. Total run time for me is 20min, but I'm not sure where gluteraldehyde would elute.

For derivitization I use 5N Phosphoric acid.

As for the standards, I would agree with what Judd said. Just make your own standards. We have extremley good linearity, LOD, and LOQ without the sigma formaldehyde-DNPH standards.

Thanks to you all for the help! I hope I'll be up and running next week.

How exactly do you prepare these samples? I've never done derivitization before and mine are precipitating. I have 25% Glut from sigma for STD and the product i'm testing is around 2.2%.

Hi H2oh; first of all; what is the concentration you will need to analyze?
As cody mention if you are a % level you do not need derivatization; you can even use Refraction index with IC; looks like cody and I are running the same samples.

Just out of curiosity: Many years ago I tried to do HPLC of ascorbic acid via DNPH derivatization. The literature of the time indicated that a strong H2SO4 method would be best. I tried all kinds of variations, but couldn´t stop the method from being very messy. Most of the mess came out ahead of the desired derivative(s), but most is not all. Worst was that the tendency to form what I called phantom peaks, namely inconsistently appearing peaks, that interfered sometimes.
I finally gave up on this approach due to difficulties with the osazones which form in this derivatization. That is, one gets two substances out of one to analyze, plus these osazones interconvert at room temp. (I had conditions where this was considerably slower than the chromatography).
Now these were the problems with standard ascorbic acid, so I just wonder how some people get these super results with this derivative (even if the compounds are "more simple").
Also why use 360 nm and not visible detection?

I've been looking all over google for a sample prep for this method. I keep finding slight clues and thats it. When you add DNPH is the sample supposed to precipitate and then you clean the precipitate and dissolve it in mobile phase??

I find many methods for the HPLC setup and whatnot, but having trouble with this derivitization prep.....any help would be greatly appreciated. Currently cleaning up my DNPH with ACN.

There is an EPA method (8315) that has similar methods. You will probably have to find one or more journal articles if the free ones aren't providing much information.

I have done glutaraldehyde by a variation of this method down to low ppb levels, and even got my Agilent autosampler to do all the work, so it is possible if you work at it.