市场上橄榄油掺假现象屡禁不止,传统鉴定方法存在局限性。本研究利用元素分析仪-稳定同位素比质谱仪(elemental analyzer-isotope ratio mass spectrometer,EA-IRMS)对市场上常见的7种植物油进行氢、碳稳定同位素比值检验,并对测量结果...市场上橄榄油掺假现象屡禁不止,传统鉴定方法存在局限性。本研究利用元素分析仪-稳定同位素比质谱仪(elemental analyzer-isotope ratio mass spectrometer,EA-IRMS)对市场上常见的7种植物油进行氢、碳稳定同位素比值检验,并对测量结果进行显著性差异分析,同时分析橄榄油中氢、碳稳定同位素比值的相关性。结果表明:橄榄油中δD范围为-146.78‰~-125.30‰,δ^(13)C范围为-29.72‰~-28.59‰,与其他品类植物油中氢稳定同位素比值差异显著(P<0.05),与除葵花籽油、野山茶油外的植物油中碳稳定同位素比值差异显著(P<0.05);且橄榄油中氢、碳稳定同位素比值具有较强的相关性(Pearson’s r=0.904)。计算模拟豆油、玉米油对橄榄油掺假的情况,结果表明,氢、碳稳定同位素比结合分析最低能检测出玉米油掺假10%、豆油掺假30%以上的情况。该研究可为橄榄油的掺假鉴定提供方法参考。展开更多
同位素比率质谱仪(isotope ratio mass spectrometers,IRMS)是近些年发展起来的用于测定某些稳定同位素组成的仪器,在诸多领域中都展现出广阔的应用前景。由于稳定同位素组成中蕴藏着丰富的地球化学信息,通过研究其组成可以揭示地球化...同位素比率质谱仪(isotope ratio mass spectrometers,IRMS)是近些年发展起来的用于测定某些稳定同位素组成的仪器,在诸多领域中都展现出广阔的应用前景。由于稳定同位素组成中蕴藏着丰富的地球化学信息,通过研究其组成可以揭示地球化学过程中的诸多方面的信息。所以IRMS技术和同位素一起作为一种新的有效手段在地球化学研究中有着越来越广泛的应用。本文主要介绍了该技术的原理,并结合相关碳氢等稳定同位素,分别讨论了与碳氢等稳定同位素在地球化学领域及相关学科中的应用。最后讨论了该技术的发展前景与目前存在的问题。展开更多
Understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass Spectrometry（IRMS）method was developed to evaluate the ...Understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass Spectrometry（IRMS）method was developed to evaluate the extent of biodegradation of the antibiotic,sulphanilamide, in contaminated groundwater. Results indicted an enrichment in δ^（13）C of8.44‰ from-26.56（at the contaminant source） to-18.12‰（300 m downfield of the source）.These results confirm reductions in sulphanilamide concentrations（from 650 to 10 mg/L）across the contaminant plume to be attributable to biodegradation（56%） vs. other natural attenuation processes, such as dilution or dispersion（42%）. To understand the controls on sulphanilamide degradation ex-situ microcosms assessed the influence of sulphanilamide concentration, redox conditions and an alternative carbon source. Results indicated, high levels of anaerobic capacity（~50% mineralisation） to degrade sulphanilamide under high（263 mg/L）, moderate（10 mg/L） and low（0.02 mg/L） substrate concentrations. The addition of electron acceptors; nitrate and sulphate, did not significantly enhance the capacity of the groundwater to anaerobically biodegrade sulphanilamide. Interestingly, where alternative carbon sources were present, the addition of nitrate and sulphate inhibited sulphanilamide biodegradation. These results suggest, under in-situ conditions, when a preferential carbon source was available for biodegradation, sulphanilamide could be acting as a nitrogen and/or sulphur source. These findings are important as they highlight sulphanilamide being used as a carbon and a putative nitrogen and sulphur source, under prevailing iron reducing conditions.展开更多
文摘市场上橄榄油掺假现象屡禁不止,传统鉴定方法存在局限性。本研究利用元素分析仪-稳定同位素比质谱仪(elemental analyzer-isotope ratio mass spectrometer,EA-IRMS)对市场上常见的7种植物油进行氢、碳稳定同位素比值检验,并对测量结果进行显著性差异分析,同时分析橄榄油中氢、碳稳定同位素比值的相关性。结果表明:橄榄油中δD范围为-146.78‰~-125.30‰,δ^(13)C范围为-29.72‰~-28.59‰,与其他品类植物油中氢稳定同位素比值差异显著(P<0.05),与除葵花籽油、野山茶油外的植物油中碳稳定同位素比值差异显著(P<0.05);且橄榄油中氢、碳稳定同位素比值具有较强的相关性(Pearson’s r=0.904)。计算模拟豆油、玉米油对橄榄油掺假的情况,结果表明,氢、碳稳定同位素比结合分析最低能检测出玉米油掺假10%、豆油掺假30%以上的情况。该研究可为橄榄油的掺假鉴定提供方法参考。
文摘同位素比率质谱仪(isotope ratio mass spectrometers,IRMS)是近些年发展起来的用于测定某些稳定同位素组成的仪器,在诸多领域中都展现出广阔的应用前景。由于稳定同位素组成中蕴藏着丰富的地球化学信息,通过研究其组成可以揭示地球化学过程中的诸多方面的信息。所以IRMS技术和同位素一起作为一种新的有效手段在地球化学研究中有着越来越广泛的应用。本文主要介绍了该技术的原理,并结合相关碳氢等稳定同位素,分别讨论了与碳氢等稳定同位素在地球化学领域及相关学科中的应用。最后讨论了该技术的发展前景与目前存在的问题。
基金Financial support from the Natural Environment Research Council(NERC)Chinese Academy of Sciences President's International Fellowship Initiative(No.2016VEA040)is gratefully acknowledged
文摘Understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass Spectrometry（IRMS）method was developed to evaluate the extent of biodegradation of the antibiotic,sulphanilamide, in contaminated groundwater. Results indicted an enrichment in δ^（13）C of8.44‰ from-26.56（at the contaminant source） to-18.12‰（300 m downfield of the source）.These results confirm reductions in sulphanilamide concentrations（from 650 to 10 mg/L）across the contaminant plume to be attributable to biodegradation（56%） vs. other natural attenuation processes, such as dilution or dispersion（42%）. To understand the controls on sulphanilamide degradation ex-situ microcosms assessed the influence of sulphanilamide concentration, redox conditions and an alternative carbon source. Results indicated, high levels of anaerobic capacity（~50% mineralisation） to degrade sulphanilamide under high（263 mg/L）, moderate（10 mg/L） and low（0.02 mg/L） substrate concentrations. The addition of electron acceptors; nitrate and sulphate, did not significantly enhance the capacity of the groundwater to anaerobically biodegrade sulphanilamide. Interestingly, where alternative carbon sources were present, the addition of nitrate and sulphate inhibited sulphanilamide biodegradation. These results suggest, under in-situ conditions, when a preferential carbon source was available for biodegradation, sulphanilamide could be acting as a nitrogen and/or sulphur source. These findings are important as they highlight sulphanilamide being used as a carbon and a putative nitrogen and sulphur source, under prevailing iron reducing conditions.
