薄层分离-库仑滴定法测定茄尼醇

提出以２ｍｏｌ／ＬＫＢｒ－醋酸（１：３Ｖ／Ｖ）为电液,在阳极电生溴与尼醇发生反应来测定茄尼醇含量的库仑滴定法。茄尼醇与溴反应,其ｎ值为１８,对于烟叶以物中茄尼醇,以正己烷－二氯乙烷－丙醇为展开剂,用薄层色地邓以分离,用库仑滴定法进行测定 。     

废次烟叶中茄尼醇的超声提取及HPLC分析测定

废次烟叶中茄尼醇的超声提取及HPLC分析测定;超声提取;高效液相色谱;废次烟叶;茄尼醇     

高效液相色谱法同时测定烟叶中茄尼醇和辅酶Q10的含量

高效液相色谱法同时测定烟叶中茄尼醇和辅酶Q10的含量;反相高效液相色谱;二级管阵列检测器;烟叶;茄尼醇;辅酶Q10     

邻硝基苯基荧光酮褪色分光光度法测定痕量钴

研究了Ｃｏ（Ⅱ）在碱性介质催化过化氢氧化邻硝基苯基荧光酮（ｏ－ＮＰＦ）这一主影响反应 因素,建立了测定痕量Ｃｏ（Ⅱ）的新方法。灵敏度为４．３×１０６－１０ｇ／Ｌ;测定范围为０￣０．５ｎｇ／２５ｍＬ方法简便快速,用于药物维生素Ｂ１２中Ｃｏ（Ⅱ）含量的测定,样品分析结果良好。     

增敏荧光光谱法测定复方新诺明中的磺胺甲(口恶)唑

提出了在溴化十六烷基三甲铵（ＣＴＡＢ）存在下,ＰＨ为４．０的ＨＡｃ－ＮａＡｃ缓冲溶液中,增敏荧光光谱法测定复方新诺明中磺胺甲恶唑（ＳＭＺ）含量的新方法。碘胺甲恶唑浓度在０．０８－０．８μｇ／ｍＬ范围内,荧光强度与碘胺甲恶唑浓度呈良好的一性关系。方法的检出限为０．０１６μｇ／ｍＬ（６．３２＊１０＾－８ｍｏｌ／Ｌ）。方法已用于测定复方新诺明中磺胺甲恶唑的含量。     

1,9-二(4-安替比林偶氮)嘌呤酮与钯的显色反应及其用于光度法测定钯

１引言 新合成的试剂１,９－二［４－安替比林偶氮］嘌呤酮（ＢＡＰＤ）,在ｐＨ＝４．５０．的ＨＡｃ－ＮａＡｃ缓冲溶液中与Ｐｄ（Ⅱ）生成稳定的红色络合物,其λｍａｘ＝ ５１０ ｎｍ,把含量在０． １２～２．４ ｍｇ／Ｌ范围内与吸光度呈线性关系。据此建立了测定Ｐｄ（Ⅱ）的分析方法,并应用于电镀液和镀层中钯含量的测定。２实验部分２．１仪器与试剂 ＤＵ－７ ＨＳ型分光光度计（美国 Ｂｅｃｋｍａｎ公司）;７６０ ＣＲＴ型紫外－可见光分光光度计（上海第三分析仪器厂）;ＨＭ－２０Ｅ型酸度计（日本ＴＯＡ公司）。钯标准溶液…     

基于四氧杂四烯衍生物荧光增强的苯酚传感器

苯酚对固定在增塑的聚氯乙烯（ＰＶＣ）敏感膜中的２，２，７，７，１２，１２，１７，１７－八甲基－２１，２２，２３，２４－四氧杂四烯（ＴＯＥ）有可逆荧光增强作用，据此研制了测定水溶液中苯酚含量的荧光化学传感器。该敏感膜最佳组成为：５０ｍｇ ＰＶＣ、１００ｍｇ癸二酸二异辛脂（ＤＯＳ）、１．５ ｍｇ ＴＯＥ。该传感器在ｐＨ７．４的 Ｔｒｉｓ／ＨＣｌ缓冲溶液中，对苯酚的线性响应范围为４．４７×ｌ０~（－６）～４．１７×１０~（－３）ｍｏｌ／Ｌ；检出限为６．３０×ｌ０~（－７）ｍｏｌ／Ｌ；其响应时间小于３０ｓ。该传感器具有良好的重现性、可逆性和选择性，常见阴离子和阳离子不干扰测定。该传感器应用于工业废水中苯酚含量的测定，结果满意。     

流动注射—氢化物发生—非色散原子荧光光谱法直接测定海水中的砷（Ⅲ）和砷（

用流动注射－氢化物发生－非色散原子荧光光谱法对海水中Ａｓ（Ⅲ）和Ａｓ（Ⅴ）的直接测定进行了研究,氢化物发生的最佳条件为：ＫＨＢ４溶液浓度为５ｇ．Ｌ＾－１（含ＫＯＨ５ｇ．Ｌ＾－１）,流速１０．０ｍＬ．ｍｉｎ＾－１;样品酸度为１．３ｍｏｌ．Ｌ＾－１ＨＣｌ,流速４．２ｍＬ．ｍｉｎ＾－１。对基体ＮａＣｌ,ＭｇＣｌ２,ＣａＣｌ２,Ｎａ２ＳＯ４以及微量共存金属离子（Ｃｄ,Ｚｎ,Ｐｄ,Ｃｕ）的干扰实验结果表明,基体和微量共存金属离子对Ａｓ（Ⅲ）的测定没有干扰。样品中Ａｓ（Ⅴ）的测定用硫脲进行预还原,通过总量和Ａｓ（Ⅲ）的含量的差减得到Ａｓ（Ⅴ）含量,在优化实验条件下下测量方法的检出限（３σ）为０．０８ｎｇ．ｍＬ＾－１;７次测定的相对标准偏差为０．４８％－１．３０％（８．０ｎｇ．ｍＬ＾－１标准溶液）。标准曲线和标准加入法对海水     

胶束毛细管电泳法测定牡丹皮及芍药中牡丹酚和芍药甙

用胶束毛细管电泳地（ＭＥＣＣ）测定牡丹皮、白芍、赤芍及其不同炮制品的牡丹酚、芍药甙的含量,以３０ｍｍｏｌ／Ｌ磷酸盐缓冲溶液（ＮａＨ２ＰＯ４－Ｎａ２ＨＰＯ４）中含２０ｍｍｏｌ／Ｌ十二烷基硫酸钠（ＳＤＳ）的表面活性剂电解质,ＰＨ＝６．８５,于２５４ｎｍ紫外检测,实验结果线性关系良好。塔数达到４．６×１０＾４。     

饮料食品中Ge－132和Ge~（4＋）含量测定研究

本文报告了在０．０１ｍｏｌ／ＬＣＴＡＢ体系中，以Ｆ－为掩蔽剂、苯芴酮显色、用分光光度法测定饮料食品中Ｇｅ－１３２含量，最低检测限０．０５４μｇ／ｍＬ；线性范围０．５４～２７．１４μｇ／ｍＬ；回收率９６．３％～１０１．５％，并确定了Ｇｅ－１３２摩尔吸收系数（ε）３．３９×１０４。用本法测定了康寿茶、矿泉水和博士奶中Ｇｅ－１３２含量，灵敏度高、重现性和准确度好。用盐酸化本体系，研究了二氧化锗（Ｇｅ~（４＋））的含量测定，其最低检测限０．０２１μｇ／ｍＬ；线性范围１．０～２１．０μｇ／ｍｌ；回收率９５．８％～１０２．８％，Ｇｅ－１３２不干扰。饮料食品中同时存在Ｇｅ－１３２和Ｇｅ（４＋）时，本体系可分别测定两者含量。     

Simultaneous determination of the aromatic retinoids etretin and etretinate and their main metabolites by reversed-phase liquid chromatography

A rapid and simple method is described for the simultaneous determination of methyl, ethyl, isopropyl, n-propyl, isobutyl and n-butyl p-hydroxybenzoic acid esters (parabens) in cosmetics by high-performance liquid chromatography (HPLC). The method involves a single extraction of parabens with diethyl ether and clean-up on a Sep-Pak Florisil cartridge. Fat-soluble excipients in the diethyl ether extracts are removed through the cartridges with hexane-chloroform (75:25). Parabens are then eluted from the cartridges with hexane-ethyl acetate (70:30) and determined by HPLC on a reversed-phase column with water-methanol (50:50) as the mobile phase using sec.-butylpraben as an internal standard. The method was applied to samples with complicated matrices such as cream, milk lotion, lotion and cleansing foam, and the recoveries were 99.0-102.3% with coefficients of variation of 0.3-1.2%.     

液相色谱-大气压化学电离离子阱质谱法测定烟草中的游离茄尼醇

用液相色谱/大气压化学电离离子阱质谱建立了一种分析烟草中游离茄尼醇的方法。烟草样品用甲醇振荡提取30 min,在分析前无需进行其它前处理。在1.8μm快速分离C18色谱短柱上用V(甲醇)∶V(异丙醇)=85∶15等梯度洗脱实现了茄尼醇的快速分离。用不带碰撞能量的二级质谱全扫描选择监测离子m/z 613.6进行定量,检出限为0.4μg/L,RSD为1.1%,两种添加量的回收率分别为97%和99%。方法应用于不同烟草和烟草制品样品的检测分析。     

烟草各部位中茄尼醇含量分布研究

采用Kromsil ODS-1色谱柱,V(甲醇)∶V(乙醇)=55∶45混合液为流动相,在紫外检测波长设定为211 nm的高效液相色谱条件下测定了烟草中各部位提取物中的茄尼醇,其中烟叶中茄尼醇的质量分数为0.45%,其他部位茄尼醇的质量分数为:烟梗0.037%,烟茎0.0037%,烟根0.0037%,其中烟叶中的茄尼醇量最高,具有提取价值.     

高效液相色谱法测定烟叶提取物中茄尼醇的含量

 采用硅胶色谱柱 ,以正己烷 异丙醇 (体积比为 98∶2 )混合液为流动相 ,在紫外检测波长设定为 2 15nm的高效液相色谱仪上测定了烟叶提取物中茄尼醇的含量。实验结果表明 :方法在茄尼醇进样量为 1μg～ 10 μg时有良好线性关系 (Y =16 6 2 0 4X - 32 5 3,r=0 9997) ;加标回收实验 (n =6 )的平均回收率为 98 1% ,RSD为 1 9% ;方法简便 ,有良好的精密度和准确性。     

Insight into molecular characteristics of a Chinese coal via separation,characterization, and data processing

Dayan lignite was subjected to thermal dissolution sequentially with cyclohexane, acetone, and methanol. Each thermal dissolution extract was subjected to further separation/enrichment using column chromatography, which was sequentially eluted with petroleum ether, a mixture of ethyl acetate and petroleum ether (vol:vol = 1:1), and ethyl acetate. The three thermal dissolution extracts and nine enrichment subfractions were characterized by an Orbitrap mass spectrometry equipped with an atmospheric pressure chemical ionization ion source. The mass spectrometry data were also statistically analyzed by principal component analysis, which can reduce the dimensionality of data and classify multiple samples according to principal components. Identified compounds in the extracts and subfractions are classified into eight classes according to the heteroatom distribution. Hydrocarbon class is mainly presented in the petroleum ether fraction, and oxygen class, nitrogen class, and oxygen‐nitrogen class are distributed in both petroleum ether/ethyl acetate and ethyl acetate subfractions. The combination of different analytical methods enhances the understanding of coal at the molecular level and provides important data for downstream refining processes.     

小刺豆荚软珊瑚甾醇类化合物的提取、分离及鉴定

从西沙群岛海区采集的小刺豆荚软珊瑚（Lobophytummicrospiculatum）中,通过乙醇提取、乙酸乙酯-水分配、硅胶色谱分离和GC／MS分析等方法,分离、鉴定出11种甾醇。其中柳珊瑚甾醇（11）的质量分数占65.6％。22,24-二甲基-胆甾-5,22（23）-二烯-3β-醇（4）是首次从自然界发现的新化合物,它的发现为柳珊瑚甾醇的生源假说提供了进一步佐证。     

Mechanisms of decomposition of mixtures of ethyl acetate and isopropyl bromide subjected to pulsed infrared laser irradiation

The infrared laser induced decomposition of mixtures of ethyl acetate and isopropyl bromide has been studied. The ratio of the yields of products ethylene and propylene, arising from the unimolecular decomposition reactions: ethyl acetate → ethylene + acetic acid, and isopropyl bromide → propylene + hydrogen bromide, were measured as a function of the ratio of ethyl acetate to isopropyl bromide and pressure of added helium. The results indicate clearly that in these systems non-equilibrium behavior is found up to the highest pressures used (about one atmosphere). A two level kinetic model is suggested which qualitatively explains the observations.     

气相色谱法测定茶叶中多种有机磷农药残留量

 采用微量化学法和全自动固相萃取技术 ,建立了气相色谱法同时测定茶叶中 14种有机磷农药残留量的方法 ,并对样品的前处理作了一定的探讨。结果表明 ,采用程序升温 ,所测定的 14种有机磷农药在SPBTM 170 1石英毛细管柱上得到了很好的分离 ,且方法快速、灵敏 ,完全符合实际应用需要。     

Experimental and thermodynamic analysis on the solubility of valsartan in ethyl acetate + (butanone,isopropyl ether) binary solvent mixtures (from 278.15 to 323.15 K)

The solubility of valsartan in ethyl acetate + (butanone, isopropyl ether) binary solvent mixtures was measured at temperatures T = 278.15–323.15 K and pressure p = 0.1 MPa with a laser monitoring dynamic technique by a synthetic method. The experimental data were regressed by the modified Apelblat equation, the general single model and the hybrid model. The experimental data are well correlated with the above models because the mean deviations (MDs) are less than 3.79%. The mole fraction solubility of valsartan increases with increase in temperature and enrichment in butanone content, while it decreases with increased mole fraction of isopropyl ether at constant temperature. In addition, thermodynamic studies, including Gibbs energy, entropy and enthalpy, were calculated by van’t Hoff analysis. The results showed that the dissolution of valsartan in mixed solvents is endothermic, spontaneous and entropy-driven.     

Activity coefficient at infinite dilution, azeotropic data, excess enthalpies and solid–liquid-equilibria for binary systems of alkanes and aromatics with esters

Binary azeotropic data have been measured at different pressures for ethyl acetate + heptane, methyl acetate + heptane, isopropyl acetate + hexane and isopropyl acetate + heptane by means of a wire band column. Additionally activity coefficients at infinite dilution have been determined for ethyl acetate and isopropyl acetate in decane and dodecane in the temperature range between 303.15 and 333.15 K with the help of the dilutor technique. Furthermore excess enthalpies for the binary systems methyl acetate + hexane, methyl acetate + decane, ethyl acetate + hexane and ethyl acetate + decane at 363.15 and 413.15 K have been studied with the help of isothermal flow calorimetry. Finally solid–liquid equilibria for the systems ethyl myristate + benzene and ethyl myristate + p-xylene have been investigated by a visual technique. All these data have been used for the revision and extension of the group interaction parameters of the group contribution method modified UNIFAC (Dortmund) and the group contribution equation of state VTPR. The experimental data was compared with the results predicted using the group contribution method modified UNIFAC (Dortmund) and the group contribution equation of state VTPR.