HPAEC PAD

[Harry64]

Hi All ,

I just start working HPAEC PAD ... first runs ok , +/- 100 samples ... suddenly no retention , only flatline ... I did'n t change the conditions ... What could be the reason ?

[HPLC chemist]

You have an electrical bad connection or a leak or...

[mattmullaney]

Hi Harry64,

What is the condition of the electrode that you're using? These days there are "cards" where the electrode is swapped into and out of the detector cell, in earlier versions of the IPAD the electrodes had to be cleaned much in the same way as a MS source. How were the responses for standard injections...did they decrease in value as the sequence(s) progressed?

[Harry64]

Hi all again ,

Working with HPAEC PAD ... bad respons on peak .. 3 x lower than expect .
Changed , disposable gold electrode , eluents ( new NaOH , H2O ... ) new reference electrode calibrated ... also working with inguard H system ...
still bad respons afterwards ...

What could be the cause of this ? Carbonates-contamination , column , guard column ,

many thanks for answer ...

[John Guajardo]

Hi Harry64,

Please contact me offline (john.guajardo@thermofisher.com) and I will help you with this issue. Please include a Chromeleon cmb(x) backup file of a few recent injections or sequence when everything was working properly vs. now with the decreased response.

[Harry64]

Hi Harry64,

Please contact me offline (john.guajardo@thermofisher.com) and I will help you with this issue. Please include a Chromeleon cmb(x) backup file of a few recent injections or sequence when everything was working properly vs. now with the decreased response.

Hi John , I send you the chromeleon file tomorrow in the morning . many thx in advance ...rgrds H64