Fabrication of a porous hydrangea-like FeO@MnO composite for ultra-trace arsenic preconcentration and determination.

FeO@MnO magnetic composite microsphere with hierarchical shells structure has been synthesized through a facile two-step hydrothermal reaction for ultra-trace arsenic enrichment. Scanning electron microscopy and transmission electron microscopy images clearly indicated that the as-synthesized material is a porous hydrangea-like morphology, as well as the size of the composite microspheres and the widths of pore are related to the reaction conditions. The N adsorption-desorption isotherms demonstrated that the specific surface areas and pore volume of FeO@MnO with 8 h hydrothermal synthesis are 121.

Dual-frequency ultrasound assisted-enzyme digestion coupled with atomic fluorescence spectrometry as a green and efficient tool for cadmium detection in rice flour samples.

A sample treatment technique based on a duel frequency ultrasonic device for enzymatic digestion of rice is reported. The ultrasonic device combines a high intensity ultrasonic probe and the temperature control function of ultrasonic water bath, which can effectively extract cadmium from rice within only 160 s under the optimized conditions. Compared with the traditional ultrasonic assisted enzymatic digestion, the new method not only shortens the time significantly (e.