Eliminating Bubble Problems in Ion Chromatography
Dissolved gasses in liquid chromatography eluents may increase background levels and can cause bubble formation that severely disturb the baseline and analyses.
When performing ion chromatography separations with suppressed conductivity detection for analysis of anions, the penalties of dissolved gasses are typically poorer signal to noise ratio and consequently worse detection levels. The dissolved gasses can also lead to failed analysis if bubble formation coincide with analyte elution and thus disturb peak integration.
A convenient way to eliminate all such problems is to install an online degasser between the eluent reservoir and the pump. The laboratory at Diduco AB in Umeå (diduco.com) has a number of analytical ion chromatography instruments from several manufacturers installed, and they have fitted Biotech DEGASi™ PLUS Classic degassers with 480 µL internal volume to most of these systems to improve results. “We have noted significantly more stable output from our ion chromatography analysis after installing degassers”, says Tobias Jonsson, CEO at Diduco AB. “The most distinct effect was in our quality control where we consistently use rather weak hydroxide eluents at high flow rates to test every suppressor we manufacture”.
Data from Diduco’s ion chromatography setup for suppressor quality control shows that the background level decreased about 30% and noise reduced by more than 40% when a degassed was installed. The degasser also completely eliminated the random bubble formation that otherwise would have disturbed these test procedures.