By comparing three sequential extraction pro- cedures, a new optimized extraction scheme for the molyb- denum association in environmental samples was proposed. Five operational steps were described as exchangeable （...By comparing three sequential extraction pro- cedures, a new optimized extraction scheme for the molyb- denum association in environmental samples was proposed. Five operational steps were described as exchangeable （KH2PO4 ＋ K2HPO4： including water-soluble）, associated with organic matter （NaOH）, Fe-Mn oxides and/or carbonates （HC1）, sulfides （H2O2） and residue （HNO3 ＋ HF ＋ H2O2）. An optimized extraction scheme was com- pared with Tessier＇s procedure and the Commission of European Communities Bureau of Reference （BCR） was applied to black shales. Results showed Tessier＇s procedure gave the lowest concentration values for exchangeable molybdenum and the highest values for the residual molybdenum, which could not present the efficiency of the extraction reagents. BCR＇s procedure showed the highest values in oxidizable molybdenum and presented four fractions of molybdenum, which did not demonstrate the fractions of molybdenum in the black shales in detail. The optimized extraction scheme demonstrated a certain improvement on extraction efficiency over Tessier＇s proce- dure for the lowest residual molybdenum, and revealed morefeatured fraction information of molybdenum in black shales than BCR＇ s. Therefore, after a comparison with other two extraction procedures, the optimized extraction scheme proved suitable for the molybdenum in black shales and it also showed an accurate determination of the molybdenum in the fractions and source of bioavailable Mo.展开更多
基金financially supported by the National Key Basic Research Program of China (2014CB238903)the Natural Science Foundation of China (41073017,41273029)the Opening Fund of State Key Laboratory of Environmental Geochemistry
文摘By comparing three sequential extraction pro- cedures, a new optimized extraction scheme for the molyb- denum association in environmental samples was proposed. Five operational steps were described as exchangeable （KH2PO4 ＋ K2HPO4： including water-soluble）, associated with organic matter （NaOH）, Fe-Mn oxides and/or carbonates （HC1）, sulfides （H2O2） and residue （HNO3 ＋ HF ＋ H2O2）. An optimized extraction scheme was com- pared with Tessier＇s procedure and the Commission of European Communities Bureau of Reference （BCR） was applied to black shales. Results showed Tessier＇s procedure gave the lowest concentration values for exchangeable molybdenum and the highest values for the residual molybdenum, which could not present the efficiency of the extraction reagents. BCR＇s procedure showed the highest values in oxidizable molybdenum and presented four fractions of molybdenum, which did not demonstrate the fractions of molybdenum in the black shales in detail. The optimized extraction scheme demonstrated a certain improvement on extraction efficiency over Tessier＇s proce- dure for the lowest residual molybdenum, and revealed morefeatured fraction information of molybdenum in black shales than BCR＇ s. Therefore, after a comparison with other two extraction procedures, the optimized extraction scheme proved suitable for the molybdenum in black shales and it also showed an accurate determination of the molybdenum in the fractions and source of bioavailable Mo.
