The work reported here is a continuation of earlier work1 in which ultrasound is found to promote ion exchange but is less effective than mechanical agitation. Correspondingly, an effort has been made to study the effect of ultrasound on adsorption by a non-polar adsorbent, XAD-2 resin. The present work shows, as in the previous case of ion exchange resins, that the rate controlling step is also a diffusion process in the uptake by the non-polar XAD-2.

An ultrasonic atomiser has been attached to a commercial atomic absorption spectrophotometer and a comparison made between the performance of ultrasonic and pneumatic atomisers in respect of sample consumption, absorbance measurements, stability and droplet size. The principal finding is that, with the ultrasonic atomiser, the same sensitivity as given by a standard pneumatic atomiser can be achieved on a considerably smaller sample volume. Further improvements in the technique should be possible.