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[目的]利用超高效液相色谱-三重四级杆串联质谱(UPLC-MS/MS),检测底泥中灭草松除草剂残留。[方法]底泥样品经索氏提取,C_(18)固相萃取柱净化后,在多反应监测(MRM)负离子电喷雾模式下进行UPLC-MS/MS分析。色谱柱为BEH C_(18)反相柱(50.0 mm×2.1 mm,1.7μm),流动相为梯度变化的乙腈和2 mmol/L乙酸铵+0.1%甲酸水溶液。[结果]灭草松的检出限(S/N≥3)为0.3μg/kg,在各自的考察浓度范围内线性关系良好(r≥0.998);在1.0~20.0μg/kg添加水平内,平均加标回收率在82%~116%之间,RSD为3.6%~9.7%。[结论]利用该方法可以实现底泥中灭草松除草剂残留量的高灵敏度检测。 相似文献
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[目的]建立土壤中灭草松、莠去津和2,-4滴的快速分析方法。[方法]建立了快速溶剂萃取一固相萃取净化一超高效液相色谱法测定土壤中的灭草松、莠去津和2,-4滴农药。[结果]优化了快速溶剂萃取条件,影响快速溶剂萃取的4种因子显著性为溶剂类型〉溶剂体积〉静态萃取时间〉提取温度。最佳快速溶剂萃取条件:温度=120℃,M土壤/V提取溶剂=1:3,溶剂为乙腈,静态萃取时间为15min。检出限为0.01~0.05mg/kg,加标回收率在76.4%-91.3%,相对标准偏差RSD〈10%(n=7)。[结论]该法操作方便,灵敏度高,可用于土壤中灭草松、莠去津和2,4.滴的测定。 相似文献
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Herbicide sorption, degradation, and leaching in three Swedish soils under long-term conventional and reduced tillage 总被引:2,自引:0,他引:2
Mats Larsbo John Stenstrm Ararso Etana Elisabet Brjesson Nicholas J. Jarvis 《Soil & Tillage Research》2009,105(2):200-208
Soil tillage has the potential to influence water flow and solute transport through the soil by cutting continuous macropores which connect the soil surface to the subsoil. Tillage also affects soil organic carbon sequestration which may lead to different sorption and degradation properties depending on the long-term tillage practices. The objective of this study was to quantify the differences in sorption, degradation and leaching of the herbicides bentazone and isoproturon between conventional tillage (CT) and reduced tillage (RT) under Swedish conditions. Three sites, Ultuna (silty clay), Säby (loam), and Lönnstorp (sandy loam moraine till), where replicate plots had been under either CT or RT for at least 9 years, were included in the study. A higher organic carbon content had developed in the top 5 cm of RT plots compared to the 10–20 cm depth and CT plots since the establishment of the experimental treatments. Adsorption and degradation were studied in laboratory experiments and solute transport was studied in undisturbed column experiments using non-reactive tracers and herbicides. The results from the column experiments were not significantly different between tillage treatments for Säby and Lönnstorp. For Ultuna, RT resulted in a more pronounced preferential tracer transport pattern and isoproturon leaching was twelve times larger compared to CT columns. This indicates that the tillage treatment had affected the macropore connectivity only at Ultuna. Freundlich adsorption coefficients for both bentazone and isoproturon were larger (though not always significantly) in the top 5 cm of RT soil compared to the 10–20 cm depth and to CT, reflecting the higher organic carbon content. The degradation rate was also generally larger (though not always significantly) in the top 5 cm of RT soil. These results show that RT has the potential to reduce pesticide leaching. However, any such reduction may be counter-balanced by enhanced preferential flow for soils where RT results in improved macropore connectivity. 相似文献
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M. Sonia Rodríguez-Cruz Julie E. Jones Gary D. Bending 《Soil biology & biochemistry》2006,38(9):2910-2918
The extent of within-field spatial variability of pesticide degradation was characterised in topsoil and subsoil, using the compounds isoproturon, bentazone and mecoprop, which are major contaminants of groundwater and surface freshwater in Europe. Twenty topsoil samples from 0 to 15 cm depth and twenty subsoil samples from 50 to 60 cm depth were collected from a single agricultural field within a 160×90 grid. It was shown that degradation rates of all compounds declined with soil depth. Variability of pesticide degradation rates, pesticide sorption and formation of non-extractable pesticide residues was higher in subsoil relative to topsoil. Furthermore, in the subsoil, there was variation in large scale soil physicochemical composition, which did not occur in topsoil. The greater variability in pesticide degradation rates in subsoil relative to topsoil could be the result of a greater range of degradation kinetics, which could reflect greater spatial variability in the distribution and/or activities of pesticide metabolising communities. 相似文献
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