摘要
通过静态箱采样和Entech7100预浓缩仪-GC-MS分析了甲硫氨酸和土壤水分对羰基硫(COS)、二甲基硫醚(DMS)、二硫化碳(CS2)和二甲二硫醚(DMDS)等4种挥发性有机硫化合物(VOSCs)吸收或释放的影响.结果表明,土壤水分主要影响土壤COS和DMS通量.含水量低时,土壤吸收COS,释放DMS;接近或超过最大持水量时,土壤释放COS和DMS,且DMS释放速率显著增加,这可能主要受土壤Eh值的影响.添加甲硫氨酸后,土壤DMDS和DMS释放量显著增加,两者释放量接近所观测四种VOSCs总释放量的100%,说明甲硫氨酸是DMDS和的DMS重要前体物.DMDS与DMS释放速率峰值出现时间相同,而COS与CS2释放速率峰值出现时间基本一致,可能是不同VOSCs受不同土壤微生物和酶的影响所致.
The influence of methionine （Met） and soil moisture on the soil-atmosphere fluxes of volatile organic sulfur compounds（ VOSCs）, including carbonyl sulfide（ COS）, carbon disulfide（ CS2 ）, dimethyl sulfide（DMS） and dimcthyl disulfide （DMDS） , were studied by static chamber enclosure followed by laboratory determina- tion using an Entech 7100 preconcentrator eoupled with a Agilent 5973 GC-MS. The results showed that COS and DMS fluxes were influenced significantly by soil water contents. Soil acted as sink for COS and source for DMS at low soil moisture, but as sources for both COS and DMS with significant increase of DMS emission rates when near or exceeding the maximum water holding capacity. This might be attributed to the change of soil Eh values. DMDS and DMS emission rates increased sharply after addition of Met to soils. DMDS and DMS amounted for 99.97% of total four VOSCs, implying that Met was an important precursor for DMDS and DMS. Emission rates peaked at the same time for DMS and DMDS while emission of COS and CS2 shared a late peak, indicating that soil microorganisms and enzymes varied for their influence on the formation of VOSCs in soils.
出处
《环境化学》
CAS
CSCD
北大核心
2009年第4期574-577,共4页
Environmental Chemistry
基金
国家重点基础研究发展计划(973)课题(2002CB410803)
福建省科技计划资助省属高校项目(2008F5013)
有机地球化学国家重点实验室开放基金(OGL-200708)
关键词
甲硫氨酸
土壤水分
挥发性有机硫化合物
通量
methionine, soil moisture, volatile organic sulfur compounds （VOSCs） , flux.
