A sin wave on the chromatogram is found during monitoring the baseline of the ECD. HTEC-500
This is called pulsatile flow. Possible causes are as follows:
• There is a leakage from the flow line.
• Columns are not held by column clips properly to ground static electrical current.
• The pump washing port does not contain enough ultrapure water. Please aspirate ultrapure water
into the syringe.
Is your reference electrode more than 1 year old? If so, it is time to replace it.
If the reference electrode is relatively new but having the sin wave, please wrap the glass part of the electrode with a sponge for insulation. (Eicom provides the insulation material made with plastic for free, please contact us for this part.)
If the system is placed close to an air conditioner, heater, or other drafts please move the system.
Temperature regulation related issue. HTEC-500 shows sometimes very small oscillation. One of the way to prevent this problem is with put a reference electrode cover (RE-Cover) on. Please also confirm if a silicon tubing is put on the ECD inlet. This silicon tube and RE-Cover should be installed as default. If those are installed correctly and the baseline oscillation persists, please set the temperature up for 1 degree. See attached chromatograms of the PP-ODSII application run both with (lower) and without (upper) the RE-COV installed.