Sounds nice, but this is not a good thing. In this picture for Total Cyanide by UV digestion and amperometric analysis there are several things to check to solve this issue.
In order of cost, ease, and probability.
- Fresh reagents. Especially the NaOH. Since the sodium hydroxide flows directly over the membrane to the amp flow cell, any degradation will directly affect your results.
- New membrane. Along the same idea, the membrane is critical for a stable baseline and sharp peaks.
- When time permits, allow the system to flush. Letting the reagents flow through the flow cell will settle the baseline and allow the amp cell to stabilize. I'll even set the pump to 5% and allow to run overnight.
- Reference Electrode. Thankfully these are extremely easy and cheap to service and replace. Although it is recommended to change these every 6 months, I find they last a lot longer.
- New pump tubing. Replace the colored tygon tubing that lays over the peristaltic pump and remember the smallest ORN/BLU platen needs to be a slightly tighter than all the rest of the lines.
- Polish working electrode. Cleaning this surface will allow for a greater sensitivity especially if the silver electrode is fairly oxidized. Gently scrub with polishing compound but in a pinch you can use a dap of toothpaste.
- Replace Amp wires (A002299). These three wires transmit the signal to the detector much like a volt meter.
- Replace Teflon digestion coil or at least try bypassing the UV digester all together to see if peaks improve.
I describe the steps above to show the process upon which I followed to eliminate all possibilities for the peaks I am showing below. Unfortunately, these were all unsuccessful due to the instrument being moved several times and some electronic damage occurred. This was only fixed by replacing a board inside the chassis, but the process is the essential for diagnosis.
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