Hi i'm busy analysing sugars in different bean species, i'm usin a carbopac PA100 column and using gradient elution. Between the times 0 and 55 minutes i gradually increase the amount of sodium acetate to 100% and decrease that of sodium hydroxide to 0%. At exactly 15 minutes, my baseline drifts from an almost zero nC to about 15 and from thee it continues increasing and at the end of the run at 60 minutes the baseline is at about 30 nC. i can't seem to detect the cause of this please help.

It is because your sodium acetate has an absorbance which is being picked up by the detector. As you increase the amount of sodium acetate, the baseline will go up. In some cases, one can "see" the gradient change based on the increase in the baseline.

thank you very much i'll try to work with low percentages of sodium acetate

i re-read the advice which was kindly given to me an i relised that i'm not detecting the absorbance of the sugars. i'm using an integrated pulsed electrodetector and so how would the absorbance of the sodium acetate affect this.

thanks the sodium acetate was the one affecting the baselind i changed the the amount of sodium acetate and now the baseline is almost linear