Acoustic effects in chromatography

An acoustic field effectively affects chromatographic retention in some sep aration modes and, thus, can be a novel factor controlling retention. After being transmitted into the column, ultrasound energy is mostly converted i nto heat as a result of absorption by stationary and mobile phases. Thus, u ltrasound brings about temperature increases. However, actual temperature i ncreases measured by thermosensors are smaller than those calculated from c hromatographic retention changes. In addition, larger ultrasound effects ar e observed in chromatographic modes involving ionic interactions. These res ults possibly imply that ultrasound directly influences ionic interactions involved in retention mechanisms. (C) 1999 Elsevier Science B.V. All rights reserved.