Palladium nanoparticles as the modifier for the determination of Zn, As, Cd, Sb, Hg and Pb in biological samples by ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry

Palladium nanoparticles (Pd-NPs) were used as the modifier for the determination of Zn, As, Cd, Sb, Hg and Pb in biological samples by ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry (USS-ETV-ICP-MS). The preparation and characterization of palladium nanoparticles (Pd-NPs) is described. Compared to traditional Pd aqueous solution, better ion signals were obtained when Pd-NPs was used as modifier. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. The introduction of dry aerosol with ETV sampling device alleviated the spectral interferences effectively. This method has been applied for the determination of Zn, As, Cd, Sb, Hg and Pb in NISTSRM 1568a Rice Flour and SRM 1573a Tomato Leaves reference materials and two biological samples obtained locally. The analysis results of the reference material agree with the certified values. The results for the real world samples were also found to be in good agreement with the pneumatic nebulization ICP-MS results of the sample solutions. The method detection limits estimated from standard addition curves are in the range 1.9-3.6, 0.2-0.4, 0.5-0.8, 0.1-0.2, 0.4-0.8 and 0.4-0.6 ng g(-1) for Zn, As, Cd, Sb, Hg and Pb, respectively, in original samples.