Search

New functionalized magnetic nanoparticles as solid-phase sorbent were prepared and investigated for extraction of ultra-trace amounts of mercury from environmental samples. The FeO magnetic nanoparticles functionalized with dithizone were characterized by Fourier transform infrared spectrometer. X-ray diffraction and scanning electron microscopy confirmed the size of nanoparticles. Effects of several factors on the extraction procedure were investigated. The optimized conditions were established to be 80 mg of polymer, 8.5 for solution pH, 5 min for adsorption time, 5 min for desorption time, 2 mL for HCl (0.1 mol L)/ thiourea 0.05 % as the eluent, 500 mL for breakthrough volume, and without addition of salt. Under the optimal conditions, the limit of detection, maximum capacity, and preconcentration factor were 0.05 ng mL, 0.557 mmol g, and 250, respectively. Limit of quantification was in the range of 0.2-2 ng mL for various matrices. Accuracy and precision of the method were about ±2.0 and below 11.1 %, respectively. Finally, the present method has been successfully applied to mercury determination in table salt, green tea, vegetables, toothpaste, and water samples. The mercury content found in the real samples was from 0.6 to 15.74 ng mL without addition of mercury. [ABSTRACT FROM AUTHOR]

An inductively coupled plasma mass spectrometry method was established for direct determination of some (ultra)trace elements in salt samples applying aerosol dilution approach. As the method does not require any sample pretreatment, contamination risk was very low, and analytical features were excellent. The method detection limits were 12, 6, 18, 2, 34, 68, and 87 ng/l for Cr, Mn, Fe, Co, Ni, Cu, and Zn, respectively. The combinatorial use of collision/reaction cell, and kinetic energy discrimination was found to be very effective to eliminate polyatomic interferences. The accuracy of the method was validated by the analysis of certified reference materials, CWW-TMG waste water and SEM-2011 water sample in high-salt matrix, 0.5 % ( w/ v) NaCl solution. The relative standard deviations were lower than 11 % for all elements without any sample pretreatment. The spike recovery values were 96-101 % at 0.2 and 1.0 μg/l, showing the applicability of the presented method for direct (ultra)trace analysis of edible salt samples. [ABSTRACT FROM AUTHOR]