Chromatography Forum

We want to quantify EDTA Disodium in Finished product by reverse phase any ideas?? I was thinking to convert it into Fe or Cu complex and then analyse it, but not sure how to prep sample.

Thanks in advance

Below is an application for EDTA - chelates using Unison UK-Phenyl:
http://www.silvertonesciences.com/files/TI261E.pdf

Ion pairing is required to improve retention.

You are not going to have too much retention on RP column.

Here is method on mixed-mode HPLC column using Cu-complex visualization- extremely sharp peaks due to focusing effect, high sensitivity; we have at least 3 big pharma companies who did cleaning validation for EDTA using this approach:

http://www.sielc.com/compound_298.html

We analyze for EDTA in a pectin preparation by converting to iron(iii) chelate and then ion-pair reverse phase as on the Silvertone application but with a C18. That may not separate different metal chelates, but we only have the iron so it works for us.

Hi Noser222,

May I know how did you prepare your Fe(III) complex (at what PH and condition EDTA disodium will form complex with Fe).What's your MP PH? any information would help me.

Thank you.

We make a 20 mM acetic acid/sodium acetate buffer, pH about 4.5. In that buffer we dissolve FeCl3 at 10 mM and dilute it to 0.2 mM for dissolving our samples.
Our mobile phase is 95% acetate buffer with 1 mM tetrabutylammonium bromide and 5% methanol, flow 1 mL/min on a 4.6 x 150 C18. We get a retention time of around 14 min. If the column has not been used with tetrabutylammonium, then equilibrate it with a higher concentration. 1 mM is on the low side, but it seems to work and no one feels like re-validating.

Noser222,

Thanks alot for the information, I will try it out today

We also make a copper complex and use an RP-8 column to assay for EDTA.

In the past I worked for Astra (nowadays Astrazeneca) and had a lot of trouble with the determination of EDTA [messing around with metals etc]

Today, it is a "piece of cake" by using ZIC®-HILIC and standard conditions, http://www.sequant.com/sn/ufiles/SeQuan ... 00-34A.pdf

May I know how did you prepare your Cu complex (at what PH and condition EDTA disodium will form complex with Cu and what is the Mobile Phase PH).

Thank you

Nosser222,

I tried the way you told, for EDTA std its working fine but in my sample (Oral Solution) I am getting a very broad peak

Thanks

You can try to go to smaller particles or use gradient on your C18 column, although I am not sure that you will get as sharp peaks as in our application (Primesep D column). Extremely sharp peak is obtained due to focusing effect for charged analyte (EDTA in this case)

You can try to go to smaller particles or use gradient on your C18 column, although I am not sure that you will get as sharp peaks as in our application (Primesep D column). Extremely sharp peak is obtained due to focusing effect for charged analyte (EDTA in this case)

Can Primesep B column be used instead of Primesep D for determination of EDTA?

Here is application for analysis of EDTA in HILIC/ion-exchange mode:
https://helixchrom.com/compounds/ethyle ... etic-acid/

For UV you can try visualization with copper ions in the mobile phase.