Ultrasonic nebulization of liquid samples for analytical inductively coupled plasma-atomic spectroscopy: an update

An improved, continuous-flow ultrasonic nebulizer equipped with a desolvation system for generating dehydrated aerosol particles prior to their injection into analytical inductively coupled plasmas is described. Results of a critical evaluation of the performance of the nebulizer-desolvation system are also presented. Compared to the commonly used pneumatic nebulizers studied in this work, the ultrasonic version described in this paper provided superior powers of detection, ranging from factors of 5–50, and yielded comparable to superior short and long term reproducibility for dilute acid and high salt content solutions. Clean out times for the ultrasonic nebulizer were marginally longer, by 15–20 s, than those observed for pneumatic nebulizers. “Memory effects” and “desolvation interferences” were generally reducible to negligible proportions through the application of various expediencies discussed in this paper. When substantial changes in concomitant concentrations caused measurable interelement effects, the magnitude of these effects tended to be slightly higher for the ultrasonic system. However, when the samples destined for ultrasonic nebulization were diluted by factors of ~ 10, which corresponds approximately to the superiority of the nebulization efficiency of the ultrasonic nebulizer, the magnitudes of the interelement effects were comparable.