目的:对LC-UV和LC-MS在山楂叶多元酚类成分分析中的应用进行方法学比较。方法:采用高效液相色谱并联双检测器(VWD和MSD)法。色谱柱为Lichrospher C18(250×4.6 mm I.D.,5μm);流动相A为乙腈,B为0.5%甲酸溶液,梯度洗脱,0-12 min A由1...目的:对LC-UV和LC-MS在山楂叶多元酚类成分分析中的应用进行方法学比较。方法:采用高效液相色谱并联双检测器(VWD和MSD)法。色谱柱为Lichrospher C18(250×4.6 mm I.D.,5μm);流动相A为乙腈,B为0.5%甲酸溶液,梯度洗脱,0-12 min A由11%-17%,12-30 min A由17%-18%,30-45 min A由18%-40%,45-60 minA由40%-100%;流速为1ml/min,三向分流阀分流进入MSD和VWD进行检测;柱温30℃;进样量10μl。结果:LC-MS灵敏度比HPLC法高10倍以上,在检测样品中微量成分时具有很大的优势;另外,LC-MS是根据tR和m/z两项指标来确定成分的类型,对于某些用LC-UV方法不能得到良好分离的组分或在LC-UV图谱上保留时间与对照品相近的其它成分,可以选用选择性离子检测(SIM)进行分析,能避免这些成分的干扰,因而具有高度的选择性和专属性。而LC-UV法操作简便,成本低,流动相选择面较广,因而分离度往往比LC-MS高,在检测样品中具有较好的紫外吸收、较好的分离度以及含量较高的成分时,LC-UV法以其高精密度和高稳定性完全可以达到LC-MS同样的检测结果。结论:LC-MS和LC-UV在山楂叶多元酚类成分的定量分析方面各有特色,可根据不同的检测指标选用不同的检测器。展开更多
High-plastic clays with significant volume change due to moisture variations present critical challenges to civil engineering structures.Limestone calcined clay cement(LC3),an innovative and sustainable hydraulic bind...High-plastic clays with significant volume change due to moisture variations present critical challenges to civil engineering structures.Limestone calcined clay cement(LC3),an innovative and sustainable hydraulic binder,demonstrates significant potential for improving the engineering characteristics of such soils.Nevertheless,the impact of LC3 on the physico-mechanical characteristics of treated soil under a cyclic wet-dry environment remains unclear.This study for the first time investigates LC3's impact on the long-term durability of treated high-plastic clays through comprehensive macro-micro testing including physical,mechanical,mineralogical,and microstructural investigations with an emphasis on wet-dry cycles.The results revealed that LC3 treatment exhibits significant resistance to wet-dry cycles by completely mitigating the swelling potential,and a considerable reduction in plasticity resulting in enhanced workability.The compressibility and shear strength parameters have been significantly improved to several orders of magnitude.However,after six wet-dry cycles,a slight to modest reduction is observed,but overall durability remains superior to untreated soil.Cohesive and structural bonding ratios quantitatively assessed the impact of wet-dry cycles emphasizing the advantage of LC3 treatment.According to mineralogical and microstructural evaluation,the mechanism behind the adverse effects of wet-dry cycles on the compressibility and strength behavior of LC3-treated soil is mainly attributed to:(1)weakening of CSH/C(A)SH and ettringite(AFt)phases by exhibiting lower peak intensities;and(2)larger pore spaces due to repeated wet-dry cycles.These findings highlight LC3's performance in enhancing the long-term behavior and resilience of treated soils in real-world scenarios,providing durable solutions for infrastructure challenges.展开更多
文摘目的:对LC-UV和LC-MS在山楂叶多元酚类成分分析中的应用进行方法学比较。方法:采用高效液相色谱并联双检测器(VWD和MSD)法。色谱柱为Lichrospher C18(250×4.6 mm I.D.,5μm);流动相A为乙腈,B为0.5%甲酸溶液,梯度洗脱,0-12 min A由11%-17%,12-30 min A由17%-18%,30-45 min A由18%-40%,45-60 minA由40%-100%;流速为1ml/min,三向分流阀分流进入MSD和VWD进行检测;柱温30℃;进样量10μl。结果:LC-MS灵敏度比HPLC法高10倍以上,在检测样品中微量成分时具有很大的优势;另外,LC-MS是根据tR和m/z两项指标来确定成分的类型,对于某些用LC-UV方法不能得到良好分离的组分或在LC-UV图谱上保留时间与对照品相近的其它成分,可以选用选择性离子检测(SIM)进行分析,能避免这些成分的干扰,因而具有高度的选择性和专属性。而LC-UV法操作简便,成本低,流动相选择面较广,因而分离度往往比LC-MS高,在检测样品中具有较好的紫外吸收、较好的分离度以及含量较高的成分时,LC-UV法以其高精密度和高稳定性完全可以达到LC-MS同样的检测结果。结论:LC-MS和LC-UV在山楂叶多元酚类成分的定量分析方面各有特色,可根据不同的检测指标选用不同的检测器。
基金The financial support of the National Natural Science Foundation of China(Grant No.42030714)the National Key R&D Program of China(Grant No.2019YFC1509900)is greatly acknowledged.
文摘High-plastic clays with significant volume change due to moisture variations present critical challenges to civil engineering structures.Limestone calcined clay cement(LC3),an innovative and sustainable hydraulic binder,demonstrates significant potential for improving the engineering characteristics of such soils.Nevertheless,the impact of LC3 on the physico-mechanical characteristics of treated soil under a cyclic wet-dry environment remains unclear.This study for the first time investigates LC3's impact on the long-term durability of treated high-plastic clays through comprehensive macro-micro testing including physical,mechanical,mineralogical,and microstructural investigations with an emphasis on wet-dry cycles.The results revealed that LC3 treatment exhibits significant resistance to wet-dry cycles by completely mitigating the swelling potential,and a considerable reduction in plasticity resulting in enhanced workability.The compressibility and shear strength parameters have been significantly improved to several orders of magnitude.However,after six wet-dry cycles,a slight to modest reduction is observed,but overall durability remains superior to untreated soil.Cohesive and structural bonding ratios quantitatively assessed the impact of wet-dry cycles emphasizing the advantage of LC3 treatment.According to mineralogical and microstructural evaluation,the mechanism behind the adverse effects of wet-dry cycles on the compressibility and strength behavior of LC3-treated soil is mainly attributed to:(1)weakening of CSH/C(A)SH and ettringite(AFt)phases by exhibiting lower peak intensities;and(2)larger pore spaces due to repeated wet-dry cycles.These findings highlight LC3's performance in enhancing the long-term behavior and resilience of treated soils in real-world scenarios,providing durable solutions for infrastructure challenges.
