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CO2 free water for electrochemical detector
Posted: Mon Dec 04, 2017 4:46 am
by thohry
Hi all,
We are analyzing gentamicin by HPLC-ECD according to European Pharmacopoeia. And in the method they say use dioxide carbon free water for preparing mobile phase.
How could I prepare such the water. Is it OK if I use just DI water or bottled water from Merk.
Thanks for any suggestion.
Re: CO2 free water for electrochemical detector
Posted: Mon Dec 04, 2017 8:18 am
by scottythree
The EP probably has directions to prepare CO2 free water. This is from the USP:
Water, Carbon Dioxide-Free—It is Purified Water that has been boiled vigorously for 5 min or more and allowed to cool while protected from absorption of carbon dioxide (CO2) from the atmosphere, or Purified Water that has a resistivity of NLT 18 Mohm-cm.
Re: CO2 free water for electrochemical detector
Posted: Mon Dec 04, 2017 9:07 am
by thohry
The EP probably has directions to prepare CO2 free water. This is from the USP:
Water, Carbon Dioxide-Free—It is Purified Water that has been boiled vigorously for 5 min or more and allowed to cool while protected from absorption of carbon dioxide (CO2) from the atmosphere, or Purified Water that has a resistivity of NLT 18 Mohm-cm.
Thank you very much !
Re: CO2 free water for electrochemical detector
Posted: Sat Dec 09, 2017 9:48 pm
by DR
That said, I suspect that He sparging would get you there too. Once left exposed to air, your water will start to re-equilibrate to about 3ppm CO2.
Re: CO2 free water for electrochemical detector
Posted: Mon Dec 18, 2017 3:02 pm
by Markus Laeubli, Metrohm
Is it OK if I use just DI water or bottled water from Merk.
Electrochemical detection is sensitive to a lot of organic compounds. I therefore would not use DI water as it still can contain organics.
I recommend to use ultrpure water out of a purification system applying UV digestion (Millipore, Barnsted ELGA etc.).