高效液相色谱-质谱法对癍痧凉茶的化学成分鉴定及指纹图谱研究

采用高效液相色谱-飞行时间质谱(HPLC-TOF-MS)和高效液相色谱-离子阱质谱(HPLC-ITMS)对癍痧凉茶进行化学成分分析。研究结果表明,"黄振龙"和"平安堂"两种癍痧凉茶中共含有40种主要化学成分,其中17种通过与文献对照得到鉴定,13种通过与对照品比较保留时间和质谱数据得到确证。同时采用HPLC-IT-MS建立了"黄振龙"和"平安堂"癍痧凉茶的液相色谱-质谱联用指纹图谱,并采用主成分分析对41批次的癍痧凉茶的质量稳定性和一致性进行了评价。主成分分析结果表明,"黄振龙"和"平安堂"癍痧凉茶之间的化学成分和内在质量具有显著性差异,提示配方组成及生产工艺不同,应予以区分。该分析方法快速、高效、可靠,是癍痧凉茶质量控制的有效手段。     

高效液相色谱-质谱法对癍痧凉茶的化学成分鉴定及指纹图谱研究

采用高效液相色谱-飞行时间质谱(HPLC-TOF-MS)和高效液相色谱-离子阱质谱(HPLC-IT-MS)对癍痧凉茶进行化学成分分析。研究结果表明,“黄振龙”和“平安堂”两种癍痧凉茶中共含有40种主要化学成分,其中17种通过与文献对照得到鉴定,13种通过与对照品比较保留时间和质谱数据得到确证。同时采用HPLC-IT-MS建立了“黄振龙”和“平安堂”癍痧凉茶的液相色谱-质谱联用指纹图谱,并采用主成分分析对41批次的癍痧凉茶的质量稳定性和一致性进行了评价。主成分分析结果表明,“黄振龙”和“平安堂”癍痧凉茶之间的化学成分和内在质量具有显著性差异,提示配方组成及生产工艺不同,应予以区分。该分析方法快速、高效、可靠,是癍痧凉茶质量控制的有效手段。     

超高效液相色谱-四极杆飞行时间质谱法测定银黄颗粒中化合成分和主要成分

建立了超高效液相色谱-四极杆飞行时间质谱(UHPLC-QTOF-MS)测定银黄颗粒中活性成分的定性和定量分析方法。银黄颗粒经甲醇萃取后,采用RRHD SB-C18超高效液相色谱柱进行分离,以0.5%甲酸水溶液-乙腈为流动相进行梯度洗脱,21种主要化学成分在25 min内得到良好的分离。化合物的定性分析通过QTOF-MS的精确分子量测定和碰撞诱导解离(CID)实验进行,其中14个化合物得到了推导鉴定,12个化合物通过与对照品比较保留时间、精确分子量和多级质谱信息得到了结构确证。定量分析通过提取目标化合物的准分子离子峰色谱图(精确至±0.001Da)进行,12种目标化合物的线性相关系数r≥0.9961;检出限和定量限分别在0.01~0.07μg/m L和0.04~0.24μg/m L范围。方法用于测定20批银黄颗粒,银黄颗粒中12种活性成分的质量分数在0.66~62.1 mg/g范围。采用主成分分析(PCA)对这20批次银黄颗粒样品进行来源追踪,并对其质量的稳定性和一致性进行了评价。PCA得分图可将4个厂家的银黄颗粒明显区分开来,所建立的分析方法可有效用于银黄颗粒的质量评价与控制。     

固相萃取-超高效液相色谱-串联质谱测定凉茶中15种植物源性兴奋剂和外源性药物

建立了固相萃取富集净化,超高效液相色谱-串联三重四级杆质谱( UPLC-MS/MS)测定凉茶中5种植物源性兴奋剂和10种外源性消炎镇痛类药物的方法。样品经高速离心后用甲酸调节至pH 4.0,HLB固相萃取柱净化,BEH C18色谱柱分离,乙腈-0.1%甲酸梯度洗脱,串联质谱电喷雾正、负离子扫描,多反应监测(MRM)模式检测,外标法定量。结果表明,15种待测物在1.0~200μg/L范围内线性关系良好;方法检出限(S/N=3)为0.1~2.0μg/L;添加水平为2.0~100μg/L时,平均回收率为76.4%~107%,相对标准偏差(RSD, n=6)为2.8%~9.7%,日间精密度为2.7%~12.0%。本方法前处理过程简单,净化效果好,灵敏度高,适用于凉茶中植物源性兴奋剂和外源性西药的检测。     

固相萃取液相色谱串联质谱法检测尿中双酚类和卤代双酚类物质

建立了高效液相色谱串联质谱法同时检测人尿液中4种双酚类和卤代双酚类物质的方法。尿液样品经酶解后,采用PLEXA(亲水亲脂聚合物小柱)固相萃取柱净化,在AtlantisT3柱(150 mm×3.0mm,3μm)上,以乙腈-水为流动相,梯度洗脱,流速250μL/min,串联质谱负离子电喷雾多反应监测模式检测,基质匹配内标法定量分析。结果表明,4种物质平均回收率为86%~118.0%,日内精密度为2.6%~17.0%,日间精密度3.2%~18%,检出限为0.01~0.25μg/L。应用本方法测定200份人尿液样品,双酚A检出率为75%,检出浓度在0.58~50.5μg/L之间。本方法操作简单、灵敏、快速、可靠。     

SPE-UPLC-MS/MS测定环境水体中呋喃丹、莠去津、甲萘威及6种邻苯二甲酸酯类

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定环境水体中呋喃丹、莠去津、甲萘威和6种邻苯二甲酸酯的分析方法。采用Pak C18固相萃取小柱对样品进行富集和净化,甲醇-水为流动相梯度洗脱,以BEH C18柱分离,在串联质谱的多反应监测模式(MRM)下检测,外标法定量。结果表明,在优化实验条件下,9种目标化合物在0.5~20.0μg/L范围内线性关系良好,相关系数均大于0.998,方法检出限(LOD)和方法定量下限(LOQ)分别为0.05~0.12μg/L和0.2~0.3μg/L,回收率为86.0%~96.5%,相对标准偏差(RSD)小于5%。方法快速准确、回收率高,适用于环境水体中呋喃丹、莠去津、甲萘威及6种邻苯二甲酸酯的测定。     

高效液相色谱-串联质谱法测定蜂蜡中硝基呋喃类代谢物

建立了高效液相色谱-串联质谱检测蜂蜡中呋喃唑酮代谢物(AOZ)、呋喃它酮代谢物(AMOZ)、呋喃西林代谢物(SEM)、呋喃妥因代谢物(AHD)残留的分析方法。试样采用正己烷预溶解,酸性水溶液中衍生化,经HLB固相萃取小柱净化,用Agilent Eclipse Plus-C18柱(100 mm×2.1 mm,3.5μm)分离,电喷雾离子源正离子(ESI+)、多反应监测(MRM)模式串联质谱进行测定。结果表明,4种硝基呋喃类代谢物在0.5~10 ng/m L范围内均具有较好的线性关系,相关系数大于0.995。在0.5,1.0和2.0μg/kg添加水平下,样品中4种硝基呋喃类代谢物的回收率在71.8%~119.0%之间,相对标准偏差(RSD,n=6)均小于10%,方法定量限(S/N10)为0.5μg/kg。方法适用于日常蜂蜡样品中4种硝基呋喃类代谢物残留的定性、定量分析。     

超高效液相色谱-串联质谱法快速测定火锅底料中的5种罂粟壳生物碱残留

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)联用法检测火锅底料中吗啡、可待因、那可丁、罂粟碱、蒂巴因5种生物碱残留的分析方法。样品经含0.2%甲酸的乙腈提取,PRi ME HLB固相萃取小柱快速净化,ACQUITY BHE C18色谱柱(1.7μm,2.1 mm×50 mm)分离,以p H 8.0氨水溶液和乙腈作为流动相,梯度洗脱,经电喷雾正离子(ESI+)模式电离及多反应监测(MRM)测定目标化合物,采用基质标准溶液曲线法定量分析。结果表明,吗啡、可待因的线性范围为0.25~100μg/L,蒂巴因的线性范围为0.05~100μg/L,那可丁、罂粟碱的线性范围为0.05~10μg/L,相关系数均大于0.999。5种生物碱的检出限为0.9~4.5μg/kg,定量下限为3.0~15.0μg/kg;在1、5、10μg/kg(吗啡和可待因为5、25、50μg/kg)3个加标水平下的回收率为70.7%~109.6%,相对标准偏差小于11%。该方法操作快速简单、灵敏度高,适用于火锅底料中罂粟壳生物碱残留的定性与定量分析。     

凝胶色谱-气相色谱-串联质谱法筛查茶叶中27种禁用农药

建立了茶叶中27种国家禁用农药的气相色谱-串联质谱分析方法。以27种国家禁用农药为目标分析物,样品经环己烷-乙酸乙酯超声提取、凝胶渗透色谱净化后进行定性和定量分析。方法检出限为0.02~2.82μg/kg,方法定量限为0.07~9.40μg/kg,在0.01~0.20 mg/L范围内方法线性相关系数均大于0.991,75%以上的农药的回收率在70%~110%之间,相对标准偏差在0.53%~7.1%之间。方法适用于茶叶中多种农药残留的检测分析。     

高效液相色谱-串联质谱法测定动物肝脏中20种全氟烷基类化合物

建立了Qu ECh ERs-高效液相色谱-串联质谱(HPLC-MS/MS)同时测定动物肝脏中20种全氟烷基类化合物(Perfluorinated alkyl substances,PFAS)残留量的分析方法。样品用0.1%HCl-乙腈振荡提取,C18、N-丙基乙二胺(PSA)和石墨化碳黑(GCB)净化,在C18色谱柱,以5 mmol/L NH4Ac甲醇溶液和5 mmol/L NH4Ac溶液为流动相进行梯度洗脱。多反应监测(MRM)负离子模式,采用基质匹配同位素内标法和外标法结合进行定量分析。20种PFAS在0.1~10μg/L浓度范围内呈线性关系,相关系数不小于0.995;检出限为0.05~0.2μg/kg,定量限为0.4~0.5μg/kg。动物肝脏中20种PFAS的3个浓度水平(0.5,2和5μg/kg)加标的平均回收率为70.3%~108.1%,相对标准偏差(RSD)在2.1%~11.9%(n=6)之间。     

Gels from a semifluorinated n-alkane in fluorinated solvents as a probe for intermolecular interactions

Diblock semifluorinated n-alkanes can form aggregates and gels in fluorinated solvents. We have investigated the thermal behavior of binary mixtures comprising F(CF₂)₈(CH₂)₁₆H and fluorinated solvents. The solvents were perfluorohexane, perfluoroheptane, perfluorooctane, perfluorooctyl bromide, perfluorodecalin, and perfluorotributylamine. The phase diagrams were used to calculate the activity coefficients of the two components and the main excess thermodynamic functions. The solubility and self-assembly behavior of F₈H₁₆ in the fluorinated solvents are related to the different solute–solvent dispersion interactions that depend on the polarizabilities and ionization potentials of the interacting species, and on the structural properties of the solvent.     

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性;均苯四甲酸二酐;联苯四羧酸二酐;二羟基联苯胺;聚酰亚胺;聚苯并噁唑;耐热性     

Studies on the Formation of Catalytically Active PGM Nanoparticles from Model Solutions as a Basis for the Recycling of Spent Catalysts

The paper presents basic studies on the precipitation of platinum, palladium, rhodium, and ruthenium nanoparticles from model acidic solutions using sodium borohydride, ascorbic acid, and sodium formate as reducing agents and polyvinylpyrrolidone as a stabilizing agent. The size of the obtained PGM particles after precipitation with NaBH₄ solution does not exceed 55 nm. NaBH₄ is an efficient reducer; the precipitation yields for Pt, Pd, Ru, Rh are 75, 90, 65 and 85%, respectively. By precipitation with ascorbic acid, it is possible to efficiently separate Pt, Rh, and Ru from Pd from the two-component mixtures. The obtained Pt, Pd, and Rh precipitates have the catalytic ability of the catalytic reaction of p-nitrophenol to p-aminophenol. The morphological characteristic of the PGM precipitates was analyzed by AFM, SEM-EDS, and TEM.     

HCOO在Cu(110)、Ag(110)和Au(110)表面的吸附

采用密度泛函理论(DFT)以及广义梯度近似方法(GGA)计算了甲酸根(HCOO)在Cu(110)、Ag(110)和Au(110)表面的吸附. 计算结果表明, 短桥位是最稳定的吸附位置, 计算的几何参数与以前的实验和计算结果吻合. 吸附热顺序为Cu(110)(-116 kJ·mol-1)>Ag(110)(-57 kJ·mol-1)>Au(110)(-27 kJ·mol-1), 与实验上甲酸根的分解温度相一致. 电子态密度分析表明, 吸附热顺序可以用吸附分子与金属d-带之间的Pauli 排斥来关联, 即排斥作用越大, 吸附越弱. 另外还从计算的吸附热数据以及实验上HCOO的分解温度估算了反应CO2+1/2H2→HCOO的活化能, 其大小顺序为Au(110)>Ag(110)>Cu(110).     

Transition metal complexes of the tripodal ligand 4-(2′-pyridylmethyl)-4-azaheptane-1,7-diamine. Crystal structures of [CuLCl]ClO4 and [NiL(MeCN)2](ClO4)2

The tripodal ligand 4-(2′-pyridylmthyl)-4-azaheptane-1,7-diamine has been prepared by reaction of 2-aminemethyl pyridine with acrylonitrile, followed by the reduction of the nitrile groups. Copper(II), nickel(II), zinc(II), cobalt(III) and chromium(III) complexes of the ligand have been prepared and characterized and the crystal structures of the complexes [CuLCl]ClO₄ and [NiL(MeCN)₂](ClO₄)₂ determined. The copper complex is five coordinate with approximate square pyramidal stereochemistry with the apical position occupied by a primary amine donor. The nickel complex is octahedral with the pyridine nitrogen donor lying trans to an acetonitrile ligand.     

Direct Quantitation of Phytocannabinoids by One-Dimensional 1H qNMR and Two-Dimensional 1H-1H COSY qNMR in Complex Natural Mixtures

The widespread use of phytocannabinoids or cannabis extracts as ingredients in numerous types of products, in combination with the legal restrictions on THC content, has created a need for the development of new, rapid, and universal analytical methods for their quantitation that ideally could be applied without separation and standards. Based on previously described qNMR studies, we developed an expanded ¹H qNMR method and a novel 2D-COSY qNMR method for the rapid quantitation of ten major phytocannabinoids in cannabis plant extracts and cannabis-based products. The ¹H qNMR method was successfully developed for the quantitation of cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabichromene (CBC), cannabichromenic acid (CBCA), cannabigerol (CBG), cannabigerolic acid (CBGA), Δ9-tetrahydrocannabinol (Δ9-THC), Δ9-tetrahydrocannabinolic acid (Δ9-THCA), Δ8-tetrahydrocannabinol (Δ8-THC), cannabielsoin (CBE), and cannabidivarin (CBDV). Moreover, cannabidivarinic acid (CBDVA) and Δ9-tetrahydrocannabivarinic acid (Δ9-THCVA) can be distinguished from CBDA and Δ9-THCA respectively, while cannabigerovarin (CBGV) and Δ8-tetrahydrocannabivarin (Δ8-THCV) present the same ¹H-spectra as CBG and Δ8-THC, respectively. The COSY qNMR method was applied for the quantitation of CBD, CBDA, CBN, CBG/CBGA, and THC/THCA. The two methods were applied for the analysis of hemp plants; cannabis extracts; edible cannabis medium-chain triglycerides (MCT); and hemp seed oils and cosmetic products with cannabinoids. The ¹H-NMR method does not require the use of reference compounds, and it requires only a short time for analysis. However, complex extracts in ¹H-NMR may have a lot of signals, and quantitation with this method is often hampered by peak overlap, with 2D NMR providing a solution to this obstacle. The most important advantage of the COSY NMR quantitation method was the determination of the legality of cannabis plants, extracts, and edible oils based on their THC/THCA content, particularly in the cases of some samples for which the determination of THC/THCA content by ¹H qNMR was not feasible.     

SYNTHESIS AND CHARACTERIZATION OF METAL COMPLEXES WITH AMPICILLIN

Abstract

The reaction, in water, of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with sodium ampicillinate at room temperature has allowed isolation of dimers with the following general formula [M(amp)Cl]₂ × nH₂O (n = 1.5?3.2). The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibilities and spectroscopic methods (IR, Raman, EPR and UV-Visible). A dinuclear structure based on octahedrally coordinated metal ions is proposed.     

Magnetism of metal-nitroxide compounds involving bis-chelating imidazole and benzimidazole substituted nitronyl nitroxide free radicals

Coordination compounds based on imidazole and benzimidazole substituted nitronyl nitroxide radicals with transition metal ions and trivalent lanthanide ions are described from the perspective of their magnetic properties.For the transition metal compounds the crystal structures show various metal-nitroxide dimensionalities including mononuclear (0D), one-dimensional (1D) and two-dimensional (2D) complexes. The mononuclear complexes were isolated with most metal ions of the first transition series. One copper(II) complex shows a copper(II)-radical ferromagnetic coupling (J = +75 cm⁻¹) while for the other mononuclear compounds, mainly with manganese(II), the metal-radical interactions are antiferromagnetic. The one-dimensional and two-dimensional complexes are manganese(II) compounds which show canting effects leading to weak ferromagnetism.For the trivalent lanthanide ions [La(III), Gd(III) and Eu(III)], three series of mononuclear complexes were obtained in which the metal center is bound to four, two or one nitroxide radicals depending on the counter ions and ancillary ligands. Unexpectedly, in most gadolinium(III) complexes, the Gd(III)-radical interactions were found to be antiferromagnetic in contradiction with other foundings and previous theoretical models. In support to the magnetic studies, the optical properties of the lantanide complexes have also been investigated and are briefly described.     

Simple,Selective, and Sensitive Spectrophotometric Method for Determination of Trace Amounts of Nickel（Ⅱ）, Copper （Ⅱ）, Cobalt （Ⅱ）, and Iron （Ⅲ） with a Novel Reagent 2-Pyridine Carboxaldehyde Isonicotinyl Hydrazone

A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.     

具有聚集诱导发光性质的近红外荧光染料

聚集诱导发光(AIE)现象的发现为解决传统有机荧光分子在高浓度和聚集形态下存在的荧光猝灭问题提供了最佳方案,并实现了在光电器件、化学传感、生物成像和靶向治疗等众多领域的广泛应用.随着对AIE 发光机理研究的不断深入,AIE 分子体系得到了极大的扩展.其中,一类具有给体-受体结构的AIE分子能够显著降低分子能隙,使发光分...