Volume 28, Number 5, June 2000Metallothioneins
|Page(s)||419 - 425|
Additional considerations for trace element analysis of environmental matrices using inductively coupled plasma atomic emission spectrometry with ultrasonic nebulizationM. Hoenig1, H. Docekalová2 and H. Baeten1
1 CERVA, Leuvensesteenweg 17, 3080-Tervuren, Belgium
2 Technical University Brno, Faculty of Chemistry, Veslarská 230, 63700-Brno, Czech Republic
(Received February 18, 2000; revised and accepted July 19, 2000.)
This work compares efficiencies of pneumatic and ultrasonic nebulizers and discusses drawbacks observed in trace element analyses of environmental matrices using ICP-AES with ultrasonic nebulization. The interference observed is mainly due to variable calcium content in samples; in most cases the excessive plasma loading by Ca is responsible for signal suppression of analyte elements. Such matrix effect may be managed to a certain extent using a classical internal standardisation that is discussed in details. Under well defined conditions, the ICP-AES-USN analysis of most trace elements leads to accurate results for matrices usually studied. However, due to chemical reactions occurring in the condensation stage of the ultrasonic nebulizer and subsequent analyte losses to the waste, the ICP-AES-USN analysis of copper and particularly of boron has to be avoided because it leads unavoidably to erroneous results. This drawback cannot be resolved by usual means of correction but may be overcome by using conventional pneumatic nebulizers.
Key words: Inductively coupled plasma atomic emission spectrometry -- ultrasonic nebulization -- trace elements -- environmental samples -- matrix interference -- internal standards.
© EDP Sciences, Wiley-VCH 2000