Boric acid determination

[gnikol21]

Hello to all, i need to find a method (pref HPLC) to measure the boric acid content in a opthalmic drug product. Can anyone have any suggestion?
Thnx in advance

[Fernando]

Hi gnikol21

What detectors are available to you? I think a conductometric detector would be the choice.
See the Phenomenex site for a method.

Best regards

Fernando

[gnikol21]

We have RI detector so i think i can try couple of methods i found in a quick search in internet.
Thnx Fernando

[Alfred88]

Dear gnikol21.
What is the reason why you need to determine Boric acid? It is not a DS/API.
Are you trying to reverse-engineer the buffer system of a branded product?
You can try to do a simple titration to find the desired ratio of Boric acid/Sodium borate to reach certain pH value.
Alfred

[Consumer Products Guy]

Dear gnikol21. What is the reason why you need to determine Boric acid?

In my case, we'd like to determine borates, used in some laundry detergents. Typically, we just send out for ICP analysis for boron, turns out to be cheaper, and gives us silicon level too, also of interest.

[Kreall]

Shodex Rspack KC-811 or equivalent

Mobile phase: 5 ml HCLO4 0,1N (in CH3COOH)
flow rate 1,0 ml/min
column temp: 40C
detection: RI