We've had halted production on our ICP-OES and have finally received a whole back up consumables kit and have replaced those items we evaluated during our trouble shooting process (new nebulizer, autosampler probe, water chiller etc.) Before going offline we had decided to change to a smaller capillary size on the I.S. p-pump tubing to prevent the need for excessively remaking solution/accumulating waste. As it stands things are just about up to speed, however it seems that the first couple calibration points have a stable I.S. response after which the response drops 20% +/-. I'm wondering if maybe the uptake time needs to be adjusted? The new autosampler line is also longer then the one we put to rest so maybe that can be taken into account.
I just feel some where in the sample introduction the solutions are not being mixed well or that the timing has been thrown off with the adjustment in tube length, capillary size, etc.
Any advice regarding this will be helpful.