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- Posts: 1
- Joined: Wed Apr 30, 2014 1:48 pm
- Location: Southern Tier, New York, USA
Hi All,
I've started to run into a problem with a setup that I have used before numerous times. This problem occurred seemingly overnight, and I am stuck as to how to rectify the problem.
I am currently running a Dionex ICS-3000 chromatograph with Chromeleon 6.8 using its electrochemical detection setup. I have a disposable silver electrode as the working electrode, and a pH electrode for the reference. My method is our variation on Dionex's Application Note #173 "Direct Determination of Cyanide in Drinking Water by Ion Chromatography with Pulsed Amperometric Detection (PAD)." Eluent is 63mM NaOH, made with 50% NaOH and degassed DI water. Column setup is AS/AG15. My waveform follows that of the method specified.
As I have said before, I have used this method multiple times and had relatively few issues other than noisy baseline issues. Now I am facing something that has me stuck, I am not detecting any Cyanide in my standard solutions that, from the day before, gave me no problems. The samples that I had run gave VERY strong signals, possibly fouling my electrode (one of my guesses), and I definitely should have run them diluted before running them neat. After seeing this, I replaced the working electrode and tried again. What my chromatograms show me is a nice, quiet (but not perfectly flat) baseline, but absolutely now signal coming from cyanide's retention time.
Would my problem detecting analyte be coming from having possibly ruined the column in some way that it couldn't elute to the detector? Would this be a problem with my detector, where it is not actually performing the waveform properly for some reason, and if not, would a reset of some kind fix it?
Any input is very much appreciated. I can supply more information if needed.
Thanks!
I've started to run into a problem with a setup that I have used before numerous times. This problem occurred seemingly overnight, and I am stuck as to how to rectify the problem.
I am currently running a Dionex ICS-3000 chromatograph with Chromeleon 6.8 using its electrochemical detection setup. I have a disposable silver electrode as the working electrode, and a pH electrode for the reference. My method is our variation on Dionex's Application Note #173 "Direct Determination of Cyanide in Drinking Water by Ion Chromatography with Pulsed Amperometric Detection (PAD)." Eluent is 63mM NaOH, made with 50% NaOH and degassed DI water. Column setup is AS/AG15. My waveform follows that of the method specified.
As I have said before, I have used this method multiple times and had relatively few issues other than noisy baseline issues. Now I am facing something that has me stuck, I am not detecting any Cyanide in my standard solutions that, from the day before, gave me no problems. The samples that I had run gave VERY strong signals, possibly fouling my electrode (one of my guesses), and I definitely should have run them diluted before running them neat. After seeing this, I replaced the working electrode and tried again. What my chromatograms show me is a nice, quiet (but not perfectly flat) baseline, but absolutely now signal coming from cyanide's retention time.
Would my problem detecting analyte be coming from having possibly ruined the column in some way that it couldn't elute to the detector? Would this be a problem with my detector, where it is not actually performing the waveform properly for some reason, and if not, would a reset of some kind fix it?
Any input is very much appreciated. I can supply more information if needed.
Thanks!
