Low-Temperature and Atmospheric Pressure Sample Digestion Using Dielectric Barrier Discharge.

A new sample digestion method using a double layer and coaxial dielectric barrier discharge (DBD) digestion reactor was developed for the sensitive determination of trace elements in rice samples. All the operation parameters of the DBD microplasma and other digestion conditions were carefully optimized. Three DBD-digestion modes were investigated for real matrix samples, including H2O-DBD-digestion, H2O2-DBD-digestion, and HNO3-DBD-digestion systems. Among the three modes, the H2O-DBD-digestion system provides a suitable digestion of sample without any additional chemicals, achieving environmental friendly sample treatment and eliminating the potential interferences. Under the optimized conditions, limits of detection for Mg, Mn, Zn, Cd, Cr, Co, and As were in the range of 0.01-0.35 ng g-1 by inductively coupled plasma mass spectrometry (ICPMS). The accuracy of the proposed method was checked by analysis of a certified reference material (GBW10043) and spiked samples with satisfactory results (83-113% recoveries).