Highly sensitive determination of cadmium and lead in whole blood by electrothermal vaporization-atmospheric pressure glow discharge atomic emission spectrometry

Abstract

In this study, a fast and simple method for highly sensitive detection of Cd and Pb elements based on atmospheric pressure glow discharge atomic emission spectrometry (APGD-AES) coupling with tungsten coil electrothermal vaporization (ETV) was proposed. A small amount of sample (10 μL) was dropped onto the tungsten coil, followed by drying, pyrolysis and vaporization procedures, and then the vaporized analyte was transported to APGD for excitation. The whole procedure took approximately 3 min. Multi-step heating of the ETV unit can separate matrices and solvents from the analyte, providing an advantage in detecting samples with complex matrix. Under the optimal experimental conditions, limits of detection of 0.4 μg L−1 (4 pg) for cadmium and 1.2 μg L−1 (12 pg) for lead were obtained, with relative standard deviations of 20 μg L−1 Cd and 100 μg L−1 Pb both being <5%. The accuracy of the ETV-APGD-AES system was verified by the determination of heavy metals in whole blood standard sample (GBW(E)090,251) and the practicability of the ETV-APGD-AES system were demonstrated by the determination of heavy metals in human whole blood. The results obtained by this instrument agree well with the standard values and those obtained by ICP-MS.