Analysts can optimize their separations by using combinations of two columns connected in series. This type of coupled column system produces peak separations that are a combination of separations obtained on each column.
Inadequate mobile-phase gassing may be the single largest cause of LC problems. Columnist Dolan examines bubble-problem sources and techniques that analysts can use to eliminate excess gas in the mobile phase.
The authors describe the results they've achieved by using water heated to 100–240 ºC as a liquid eluent for reversed-phase HPLC instead of an organic modifier. They point out that this alternative avoids many of the problems – toxicity, flammability, and cost – associated with organic modifiers.