Chromatography Forum

We currently have a method for analysis of EDTA that we are having problems with. At times, the area counts for the EDTA peak increase over the course of the entire run. Other times, they are very consistent.

Run 1 Run 2
705664 604274
705246 610078
702745 613880
701808 618958
699750 629232


The issue does not seem to be carryover, as there is nothing detectable in the blank injections immediately following any sample or standard injections. A brief summary of the method is outlined below.

EDTA derviatized with ferric nitrate nonahydrate solution

Buffer/Mobile Phase A is tetrabutyl ammonium bromide and sodium formate in water
Mobile Phase B is Methanol

EDTA elutes during 98% MPA and 2% MPB

The column is a Hypersil BDS C18 5 micron 4.6 x 250 mm

UV detection at 260 nm

Any insight would be greatly appreciated.

We assayed EDTA and other chelants in finished consumer products regularly using HPLC with UV detector, but with a C8 column, and isocratic elution.

If you post your E-mail address, I can share with you what we have used successfully.

Thanks for the offer, but validating a new procedure is not really an option at this moment. I am trying to see if we can find a technique to make our existing procedure perform consistently.

In addition, there are other analytes being quantified in this method, so we need to use the gradient.

Could this be a case of analyte adsorption in the HPLC system? Being a chelating agent, EDTA may bind to active sides on the steel surfaces. You may try to passivate the system using nitric acid...or as a quick fix, use some "priming" injections of a high-concentrated EDTA standard solution in order to saturate any active sites.

lately we developed a valid method for Edta analysis after derivtization with ferric chlorid we used ion pair like yours , we had some problems like drafting noise and baseline noise, we supposed that problems like this can result from reactions between ferric cations and silanol groups of the stationary bed, so we used to use relatively long run times ( let mobile phase to flow for about 15-20 min after elution of each principle peak washing the stationary phase 0.5% EDTA solution for about 30 min , this technique was very effective in removal of any iron traces on the packing and our problem was resolved , and note that ferric ions have destructive effect on silanol gps, hope that could help you with your problem

Thank you for your replies. I will try these solutions.

We assayed EDTA and other chelants in finished consumer products regularly using HPLC with UV detector, but with a C8 column, and isocratic elution.

If you post your E-mail address, I can share with you what we have used successfully.

Hi Consumer Products Guy. Would you mind sending me this method at joerg.johannes (add) laus.de?
Thanks a lot
Jörg

We assayed EDTA and other chelants in finished consumer products regularly using HPLC with UV detector, but with a C8 column, and isocratic elution.

If you post your E-mail address, I can share with you what we have used successfully.

hi,consumer products guy,would you share your EDTA assay method for me?

jerrychen428@gmail.com

thank you

We assayed EDTA and other chelants in finished consumer products regularly using HPLC with UV detector, but with a C8 column, and isocratic elution.

If you post your E-mail address, I can share with you what we have used successfully.

hi,consumer products guy,would you share your EDTA assay method for me?

jerrychen428@gmail.com

thank you

Jerry - he sent this procedure to me, said I could pass it on. So I E-mailed it.

We assayed EDTA and other chelants in finished consumer products regularly using HPLC with UV detector, but with a C8 column, and isocratic elution.

If you post your E-mail address, I can share with you what we have used successfully.

hi,consumer products guy,would you share your EDTA assay method for me?
sasidhar.boddapati@akorn.com

Thank you

We assayed EDTA and other chelants in finished consumer products regularly using HPLC with UV detector, but with a C8 column, and isocratic elution.

If you post your E-mail address, I can share with you what we have used successfully.

hi,consumer products guy,would you share your EDTA assay method for me?

jerrychen428@gmail.com

thank you

Jerry - he sent this procedure to me, said I could pass it on. So I E-mailed it.

sasidhar.boddapati@akorn.com - I E-mailed CPG's procedure.

Good morning Consumer Products Guy.

We have been doing EDTA work using UV and MS detectors on occasion. I would be interested in having a copy of your method if the offer is still there for comparison.

Thanks
Kevin

Email ksoulsbu at BCIT dot ca

hi,consumer products guy,would you share your EDTA assay method for me?

jerrychen428@gmail.com

thank you

Jerry - he sent this procedure to me, said I could pass it on. So I E-mailed it.

sasidhar.boddapati@akorn.com - I E-mailed CPG's procedure.

Dear Colleagues- I would be interested in comparing with CPG's method as well. Could someone reach me at copelandclark@hotmail.com ?

Consumer Products Guy wrote:
We assayed EDTA and other chelants in finished consumer products regularly using HPLC with UV detector, but with a C8 column, and isocratic elution.

If you post your E-mail address, I can share with you what we have used successfully.

Dear Consumer Products Guy:

If your kind offer still exists, would you mind sending me the method? Thank you so much. Lucy

liping_999@yahoo.com

Hi there
I am also still interested in receiving the details
My email is
Soulsbury@icloud.com


Thanks
Kevin