Chromatography Forum

Not having much luck with sample prep for glutaraldehyde...can anyone help me find this article instead?

Determination of Formaldehyde and Other Aldehydes in Industrial Surfactants by Liquid Chromatographic Separation of Their Respective 2,4-Dinitrophenyl-hydrazone Derivatives

Not having much luck with sample prep for glutaraldehyde...can anyone help me find this article instead?

Determination of Formaldehyde and Other Aldehydes in Industrial Surfactants by Liquid Chromatographic Separation of Their Respective 2,4-Dinitrophenyl-hydrazone Derivatives

James R. Dahlgren and Melvin N. Jameson, “Determination of Formaldehyde and Other Aldehydes in Industrial Surfactants by Liquid Chromatographic Separation of Their Respective 2,4-Dinitrophenyl-hydrazone Derivatives,” Journal of the Association of Official Analytical Chemists (Vol. 71, No. 3, 1988), pp. 560-563. I have this at work. We also use the following for glutaraldehyde.

DNPH reagent (0.12 % 2,4-dinitrophenylhydrazine in HPLC acetonitrile): weigh 0.11 – 0.13g 2,4-dinitrophenylhydrazine into a 100 ml volumetric flask; mix and dilute to volume with acetonitrile (mix well to dissolve completely).

Formaldehyde hydrazone standard (2,4-dinitrophenylhydrazone): pipet 1.00 ml formaldehyde standard solution above into a 20 ml scintillation vial; then add 4.0 ml DNPH reagent and 100 ul of 2 N HCl. Cap and mix well; allow 10 minutes derivatization time. Filter a portion through a 0.45u disposable HPLC sample filter unit into a sample vial and cap.
Make fresh daily.

Reagent blank: pipet 1.00 HPLC H2O into a 20 ml scintillation vial; then add 4.0 ml DNPH reagent (using an Eppendorf pipet or repeating dispenser) and 100 ul of 2 N HCl. Cap and mix well; allow
10 minutes derivatization time. Filter a portion through a 0.45u disposable HPLC sample filter unit into a sample vial and cap. Make fresh daily.

Weigh 1 g well-mixed liquid sample into a 20 ml scintillation vial. Add 4.0 ml DNPH reagent and 100 ul of 2 N HCl. Cap and mix well; allow 10 minutes derivatization time. Filter a portion through a 0.45u disposable HPLC sample filter unit into a sample vial and cap.

If the contribution of the formaldehyde hydrazone peak in the reagent blank is significant, subtract its average area from both the average Areastandard and the average Area sample before doing the calculations. If the size of the formaldehyde hydrazone peak in the reagent blank is so large that it would negatively affect quantitation of the formaldehyde level in the sample, purify the 2,4-dinitrophenylhydrazine by recrystallizing as specified in EPA method #8315.

How do you prepare your Glut standard and sample, what concentration are they?
Thanks so much for this!! Been really hard finding an actual sample prep for derivitization and I had no idea what that was until last week.

How do you prepare your Glut standard and sample, what concentration are they?

This will depend on what levels of glutaraldehyde you have or expect in your sample. We try to match up pretty well (in all our assays) the levels in the calibration standard and the sample for best quantitation, even if we've already demonstrated linearity, accuracy, and precision. That said, a typical glutaraldehyde standard solution: using a disposable syringe with a cap, quickly and accurately weigh (by difference) about 0.15 g glutaraldehyde and take to 100 ml. Dilute 2.00 ml of this solution to 250 ml with H2O.

For samples: Weigh 1 g liquid sample into a 20 ml vial. Add 4.0 ml DNPH reagent and 100 ul of 2 N HCl. Cap and mix well; allow 10 minutes derivatization time. Filter a portion through a 0.45u disposable HPLC sample filter unit into a sample vial and cap.

Hey, does the glut normally elute as two peaks (with poor resolution)? or is my sample degraded a bit?

What chromatographic conditins were used for this analysis? Might just have saved me some time!

Hey, does the glut normally elute as two peaks (with poor resolution)? or is my sample degraded a bit?

Hey ??? Cody, did you run a reagent blank? We get two peaks, but the first is excess DNPH reagent, the second is derivatized glutaraldehyde. the chromatogram looks like a typical one, but if you post an E-mail address I can E-mail an example to you.

What chromatographic conditins were used for this analysis? Might just have saved me some time!

That depends on your column type and dimensions. I use H2O-ACN, with some H3PO4. detector at 365nm using a visible lamp.

Just how I do this....

Wow I forgot about this! I was pulled off this project a long time ago due to priorities. I'll message you my email CPG, thanks for the info!

That depends on your column type and dimensions. I use H2O-ACN, with some H3PO4. detector at 365nm using a visible lamp.

Just how I do this....

Thanks