Fast and clean determination of total selenium in biological materials by an improved oxygen flask combustion method combined with hydride generation atomic fluorescence spectrometry

Abstract

A new method for fast and clean determination of Se in biological samples by hydride generation atomic fluorescence spectrometry (HG-AFS) was developed. An improved oxygen flask combustion (OFC) method based on quartz fabric cloth partially coated with glycerol was adopted for sample holding and igniting, and it showed larger sample mass ability and a co-existing metals separation effect in comparison with the conventional filer-paper based method. With the improved method, upper to 100 mg of sample could be decomposed in a 500 mL volume of oxygen under atmospheric pressure. In addition, a systematic study on the combustion behaviors of different Se species revealed that volatile SeO2, which was easily absorbed and dissociated in 10% HCl (v/v), was the only combustion product, thus, a more concise analytical procedure was realized since no additional reduction steps were needed prior to the subsequent HG-AFS determination. After method optimization, the whole sample treatment time of <40 min, the LOD of 0.0121 μg/g and the RSD (n = 6) of 0.834% were achieved, respectively. Finally, the method was evaluated by analysis of three certified standard materials and methods comparison was also conducted in four deer tissue samples analysis.