Matrix-bound phosphine(MBP) is a general term used to indicate non-gaseous reduced phosphorus compounds that are transformed into phosphine gas upon reaction with bases or acids.Antarctic seabird guanos and ornithogenic soils were used as materials to compare the different digestion methods for transforming matrix-bound phosphine into phosphine gas.The results demonstrated that more phosphine gas in most of Antarctic environmental materials was formed of matrix-bound phosphine by caustic digestion than by acidic digestion.The comparative study on different digestion methods also revealed that the fraction of MBP converted to gaseous phosphine during the digestion depended on the temperature.The optimal digestion temperature was close to 70℃ and the optimal digestion time was about 20 min.Acidic conditions were more favorable for the release of matrix-bound phosphine compared to the neutral conditions.A proper water dilution can increase the production and emission of phosphine from the Antarctic penguin guanos.
During the 22nd Chinese Antarctic Research Expedition(CHINARE-22,2005/06),the atmospheric gas samples near the surface were taken on the Millor Peninsula and adjacent areas,east Antarctica,using Tedlar gas bags.The methane(CH4) concentration and δ13C-CH4 in those samples were analyzed in the laboratory.The average value of atmospheric CH4 concentration on this peninsula was(1.87±0.12)×10-6,slightly higher than the global average CH4 concentration.The summertime variation of CH4 concentrations showed a large fluctuation,corresponding to the variation of air temperatures.The average δ13C-CH4 was(-38.26±0.52)‰.CH4 concentrations and δ13C-CH4 at different sites varied from 1.74×10-6 to 2.56×10-6 and from-39.31‰ to-31.25‰,respectively.The factors affecting CH4 concentrations and δ13C-CH4 values have also been discussed in this study.
