ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
A microanalytical method based on electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry for multielemental determination: comparison with inductively coupled plasma optical emission spectrometry
Tiberiu Frentiu, Sinziana Butaciu, Eugen Darvasi, Michaela Ponta, Maria Frentiu, and Dorin Petreus
Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania
Abstract: A microanalytical method based on small-sized electrothermal vaporization low power (15 W) and low Ar consumption (150 mL min−1) capacitively coupled Ar plasma microtorch and detection by optical emission spectrometry using a low-resolution microspectrometer was characterized for determination of As, Ag, Cd, Cu, Hg, Pb, Sb, Sn and Zn. Elements requiring usually either hydride (As, Sb, Sn) or cold vapor generation (Hg) were determined along with other elements using the completely miniaturized analytical system. A volume of 10 µL sample was vaporized on a Rh coil (1500 °C, 10 s), introduced into the plasma with the Ar flow followed by recording of 20 spectra episodes using the QE65 Pro microspectrometer. The emission spectrum of elements is simple, so that the coupling microtorch-microspectrometer with 0.4 nm full-width half maximum was adequate. The detection limits were in the range 1.5–40 ng mL−1, similar or better compared to those found in the reference method, inductively coupled plasma optical emission spectrometry. The new method complies with the requirements for environmental analyses and has been applied to determine elements in soil and sediment samples using the standard addition method with recovery and precision in the range 92–104% and 0.4–11.6%, respectively. The miniaturized instrumentation including the plasma microtorch is a promising alternative to inductively coupled plasma optical emission spectrometry with pneumatical nebulization.
Keywords: Electrothermal vaporization; Radiofrequency capacitively coupled plasma; Optical emission spectrometry; Inductively coupled plasma optical emission spectrometry
Full paper is available at www.springerlink.com.
Chemical Papers 71 (1) 91–102 (2017)