Determination of 46 Kinds of Elements in Plant Samples by Inductively Coupled Plasma-Atomic Emission Spectrometry with Air-cooled Reflux Digestion

Plant samples were dissolved with HNO₃ and H₂O₂ respectively in grinding conical flask placed directly on an ordinary flat aluminum electrothermal plate with an air-cooled tube. The reflux devices, consisting of 45 conical flasks can be heated simultaneously. This method keeps the sample solution under slight boiling conditions to digest the sample completely rendering the critical digestion time unnecessary. The 46 kinds of element contents in samples were determined simultaneously by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The standard reference materials for the plants(GBW 10012, GBW 10014 and GBW 10019)were analyzed and the results were in good agreement with the certified values. The relative standard deviations (n=6) ranged from 0.44% to 5.59%. Compared to the methods of microwave digestion and dry ashing, this method is simple, rapid, uses less reagents and has lower blank and salinity which make it convenient for multi-elements measurements of plant sample by ICP-MS. The operating conditions of the ICP-MS were optimized by using debugging hydraulics, and the interference relationship was studied. The interference of determination was eliminated effectively by using a mathematical model.