9Mostafa GA, Ghazy SE. Indirect spectrophotometric determination of small amounts of selenium( Ⅳ ) and arsenic ( Ⅴ ) by simple extraction using flotation columns. Anal Sci, 2001,17:1189-1193.
10Wang Z, Gao YX, Beizile N. Microwave digestion of environmental and natural waters for selenium speciation. Anal Chem, 2001,73: 4711-4716.
