A procedure for sample preparation was investigated in this work using infra-red radiation generated by tungsten lamps for fast heating of an acidic sample suspension contained in a glass flask. The main advantages of the developed procedure are its simplicity and low-cost. Additionally the dilute acid solution is heated in less than 60 s and the total sample preparation is performed in less than 5 min. The proposed procedure is suitable for trace analysis and it can be easily implemented. The preliminary investigations focus on the determination of Cu, Fe, Mn, and Zn in bovine liver and apple leaves as standard reference materials. All results are in agreement at a 95% confidence level. Copper and Mn were also determined in a sample of bovine liver without any sample pretreatment or after a freeze-drying step for comparison. For this sample, the results were validated using a conventional microwave-assisted closed vessel procedure.
Infra-red heating; sample preparation; infra-red radiation; sample decomposition
