Ultrasonic nebuliser, a useful tool for improving the sensibility of trace element detection in surface water

In order to analyse trace elements from surface water, drinking water and wastewater an analytical method using Ultrasonic Nebuliser USN U5000AT+ equipment coupled with ICP-EOS Optima 5300 DV Perkin Elmer Spectrometer has been developed. Quality parameters (LOD, LOQ) allow the detection on sensitivity level imposed by European Legislation. Optimized parameters for simultaneous determination of Cd, Cr, Cu, Co, Ni and Pb in the range 1 to 5 µg/l were: power setting of 1400 W; auxiliary gas of 0.2 l/min; nebuliser gas of 0.75 l/min; sample uptake rate of 1.9 ml/min; plasma gas rate 15 l/min. Quantification limits obtained using fortified blanks indicated low values such as: 0.075 µg/l (Cd, Co); 0.10 µg/l for (Ni, Pb); 0.15 µg/l (Cr, Cu). The use of an USN as sample introduction system instead of Meinhardt Classic Nebuliser improves LOQ more than 10 times.