Labeled polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)were extracted by three different methods,i.e.,soxhlet extraction,hot extraction and accelerated solvent extraction(ASE).The PCDD/Fs were detected by...Labeled polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)were extracted by three different methods,i.e.,soxhlet extraction,hot extraction and accelerated solvent extraction(ASE).The PCDD/Fs were detected by high resolution gas chromatography-high resolution mass spectrometry.Comparisons of the three methods were carried out by recovery of PCDD/Fs,solvent consumption and extraction time.The results showed that all of the method could extract labeled PCDD/Fs efficiently.ASE was a time saving procedure with lowest consumption of solvents compared with the other two methods.展开更多
为了实现高瓦斯矿井巷道安全快速掘进,研究了大直径长钻孔掩护巷道安全快速掘进技术,利用孔径差异优化“两堵一注”封孔工艺,依据瓦斯含量实现煤巷瓦斯分级治理,提高了瓦斯灾害防治效果及巷道掘进速度。研究结果表明:大直径长钻孔掩护...为了实现高瓦斯矿井巷道安全快速掘进,研究了大直径长钻孔掩护巷道安全快速掘进技术,利用孔径差异优化“两堵一注”封孔工艺,依据瓦斯含量实现煤巷瓦斯分级治理,提高了瓦斯灾害防治效果及巷道掘进速度。研究结果表明:大直径长钻孔掩护巷道掘进技术具有更好的卸压增透效果和更长的抽采时间,结合多孔径“两堵一注”封孔工艺,30d平均单孔瓦斯抽采浓度达到了80.2%,与常规边掘边抽钻孔相比提高3.1倍,平均瓦斯抽采纯量高达0.44 m 3/min,与常规边掘边抽钻孔相比提高10.3倍,采用该技术的巷道瓦斯浓度保持在0.27%~0.40%,月进尺达到了400 m,实现了巷道安全快速掘进。展开更多
A rapid pretreatment method of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and analysis by high resolution gas chromatograph-high resolution mass spectrometry was present.The extraction and a...A rapid pretreatment method of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and analysis by high resolution gas chromatograph-high resolution mass spectrometry was present.The extraction and alumina clean up of PCDD/Fs in soil was achieved by accelerated solvent extractor.Then the multi-layer silica-gel column was used for further clean up.The whole method has been evaluated on certified reference soil and farm soil.Accuracy and precision of this method was tested with satisfactory results.展开更多
文摘Labeled polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)were extracted by three different methods,i.e.,soxhlet extraction,hot extraction and accelerated solvent extraction(ASE).The PCDD/Fs were detected by high resolution gas chromatography-high resolution mass spectrometry.Comparisons of the three methods were carried out by recovery of PCDD/Fs,solvent consumption and extraction time.The results showed that all of the method could extract labeled PCDD/Fs efficiently.ASE was a time saving procedure with lowest consumption of solvents compared with the other two methods.
文摘为了实现高瓦斯矿井巷道安全快速掘进,研究了大直径长钻孔掩护巷道安全快速掘进技术,利用孔径差异优化“两堵一注”封孔工艺,依据瓦斯含量实现煤巷瓦斯分级治理,提高了瓦斯灾害防治效果及巷道掘进速度。研究结果表明:大直径长钻孔掩护巷道掘进技术具有更好的卸压增透效果和更长的抽采时间,结合多孔径“两堵一注”封孔工艺,30d平均单孔瓦斯抽采浓度达到了80.2%,与常规边掘边抽钻孔相比提高3.1倍,平均瓦斯抽采纯量高达0.44 m 3/min,与常规边掘边抽钻孔相比提高10.3倍,采用该技术的巷道瓦斯浓度保持在0.27%~0.40%,月进尺达到了400 m,实现了巷道安全快速掘进。
文摘A rapid pretreatment method of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and analysis by high resolution gas chromatograph-high resolution mass spectrometry was present.The extraction and alumina clean up of PCDD/Fs in soil was achieved by accelerated solvent extractor.Then the multi-layer silica-gel column was used for further clean up.The whole method has been evaluated on certified reference soil and farm soil.Accuracy and precision of this method was tested with satisfactory results.
