Electrothermal Vaporization Inductively Coupled Plasma Mass Spectrometry for the Determination of Cr, Cd, Hg, and Pb in Honeys

Abstract

Electrothermal vaporization dynamic reaction cell inductively coupled plasma mass spectrometry (ETV-DRC-ICP-MS) has been applied to determine Cr, Cd, Hg, and Pb in honey samples. Honey homogenate containing HNO₃ and ascorbic acid was prepared and injected into ETV for their determination by ETV-ICP-MS. The influences of instrument operating conditions and honey solution preparation on the ion signals were reported. Ascorbic acid was used as the modifier to enhance the ion signals. The background intensity at the chromium masses was reduced significantly by using O₂, at 1 mL min⁻¹, as the reaction cell gas in the dynamic reaction cell (DRC). As the sensitivity of analytes in homogenized honey solutions and aqueous solutions is quite different, isotope dilution and standard addition methods were used for the quantification of Cr, Cd, Hg, and Pb in the honey samples. This method has been applied to determine Cr, Cd, Hg, and Pb in several honey samples purchased from local markets. The results obtained by isotope dilution and standard addition methods were in good agreement. The method detection limits (MDLs) estimated from standard addition curves were 0.4, 0.1, 0.6, and 0.5 ng g⁻¹ for Cr, Cd, Hg, and Pb, respectively, in original honey samples.