Determination of trace Se in drinking water using online concentration graphite furnace atomic absorption spectrometry

Objective:To establish an online concentrating graphite furnace atomic absorption spectrometry(GFAAS)method for the determination of trace selenium(Se)in water.Methods:By setting the temperature control program of Thermo Elemental Solaar M5 graphite furnace atomic absorption spectrometer,the sample injection,drying and online concentration processes were repeated 5 times within one analysis period and then the absorbance was measured after ashing and atomizing procedures.The electric current of the Se light was 5.0 mA,determined wavelength was at 196.0 nm,the slitwidth was 0.5 nm.Results:Under selected conditions,Se appeared to have a good linearity(r=0.9981)in the range of 0-25 μg·L-1.The detection limit(n=11)was 1.38×10-11 g.The results showed that RSD obtained by thirteen repetitions using standard solution with 15 μg·L-1 of Se was 4.4%(n=13).The recoveries were 94.8%-106%.Conclusion:The proposed method has good repeatability and can be applied in the determination of trace Se in drinking water.