蒎酮酸合成样品的气相色谱分析

采用气相色谱法跟踪测定了α-蒎烯氧化反应中主产物蒎酮酸的含量；实验结果表明，在SE-30/Chro-mosorb W/AW(0.25-0.175mm)的色谱柱上，蒎酮酸与副产物之间具有较好的分离效果，并且在峰形对称性和出峰时间上，SE-30柱也具有优势；该法操作简便、快速、准确性高、重复性好；对同一试样的5次平行独立测定的相对标准偏差（RSD）为1.8％；该法的标准加入回收率达88％-96％。     

诺蒎酸的超声合成

以β-蒎烯为原料,通过KMnO4氧化辅以超声辐照手段,进行了诺蒎酸的合成条件优化研究.正交实验表明,声强对诺蒎酸的产率影响最大,其次为pH、原料配比、反应温度和时间;单因素实验表明,诺蒎酸的产率随着声强的增大而增大.在声强0.38W/CM2、pH=10、n(β-蒎烯)/n(KMnO4)=1/2、15℃反应30min的优...     

电子鼻测定植物挥发性有机物方法研究

建立了电子鼻技术(GC/SAW)快速实时检测植物挥发性有机物(BVOCS)的分析方法。考察了检测器温度、进样温度、柱温、升温速率等因素的影响,确定了电子鼻技术分析BVOCS的最佳条件为:检测器温度60℃、进样口温度100℃、柱温40～145℃(10℃/s)、阀温145℃、预浓缩管250℃、载气流速3mL/min。在上述条件下,测得不同时间(日内、日间)α-蒎烯和异戊二烯分别在0.027～8.580mg·L-1、0.425～68.100mg·L-1范围内线性良好;α-蒎烯和异戊二烯的回收率分别在90.74%～107.41%和91.29%～102.88%之间;相对标准偏差(RSD)均小于5%;检测限在0.2～1.0μg·L-1内。     

新型蒎酸基双酰腙类化合物的合成及其除草活性

以α-蒎烯为原料,经氧化和溴仿反应制得蒎酸(3)。在HATU作用下,3和Boc肼发生N-酰化反应得含Boc保护基的蒎酸基双酰肼(4);4脱除Boc保住基得蒎酸基双酰肼(5);5与取代苯甲醛经缩合反应合成了6个新型的蒎酸基双酰腙类化合物(6a~6f),其结构经1H NMR,13C NMR,IR,ESI-MS和元素分析表征。初步的除草活性测试表明,6a~6f在用药量为100μg·mL-1时对油菜胚根生长具有一定的抑制作用,其中蒎酸基双苯酰腙(6b)和蒎酸基双对氟苯酰腙(6d)的抑制率分别为70.1%和73.2%。     

气相色谱法测定水样中三唑磷残留量

用气相色谱法对水样中残留的三唑磷的含量进行测定.水样经苯提取,采用HP-5毛细管色谱柱(30 m×0.32 mm,0.25 μm)分离,用氮磷检测器测定.三唑磷的质量浓度在0.0051.0 mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为3.5 μg·L-1.方法的回收率在94.0%～97.5%之间,测定结果的相对标准偏差(n=6)小于3.7%.     

大体积进样-离子色谱法测定炉水中痕量阴离子

提出了大体积进样-离子色谱法测定火电厂炉水中8种阴离子F-、CH3COO-、HCOO-、Cl-、NO2-、NO3-、SO42-及PO43-的含量。水样经AG17-C保护柱及AS17-C分离柱分离,以氢氧化钾溶液为淋洗液进行梯度淋洗,采用抑制电导器检测。8种阴离子的质量浓度均在5.0～50μg·L-1范围内与峰面积呈线性关系,检出限(2S/N)在0.01～0.11μg·L-1之间,测定下限(10S/N)在0.05～0.52μg·L-1之间。方法用于火电厂炉水中8种阴离子的测定,加标回收率在97.8%～107%之间。     

固相萃取-离子色谱法测定土壤中亚硝酸盐和硝酸盐

提出了离子色谱法测定土壤中亚硝酸盐和硝酸盐的方法。土壤试样经水超声浸取,采用OnGuardⅡP和OnGuardⅡRP固相萃取柱净化,以AS11-HC为分析柱、AG11-HC为保护柱,萃取液中的NO2-和NO3-用15mmol·L-1氢氧化钾溶液洗脱分离,并用抑制电导检测器同时测定其含量。亚硝酸盐和硝酸盐质量浓度分别在0.01～1.00mg·L-1和0.10～10.0mg·L-1范围内与对应的峰面积呈线性关系,方法的检出限(3s/k)分别为0.16,0.24μg·g-1。方法的加标回收率分别在85.0%～100%和93.5%～106%之间,相对标准偏差(n=7)分别在2.9%～4.1%和2.2%～3.4%之间。     

顶空固相微萃取-气相色谱法测定水中四乙基铅

提出了顶空固相微萃取-气相色谱法测定水中四乙基铅含量的方法。为使固相微萃取达到更高的效率,选用聚二甲基硅氧烷填料(PDMS)作为微萃取的涂层,萃取温度及时间为60℃和30min。用DB-5色谱柱分离,用电子捕获检测器检测。四乙基铅的质量浓度在0.05～20.0μg·L-1范围内与峰面积呈线性关系,方法的检出限(3S/N)为0.02μg·L-1。以水样为基体,在3种浓度水平下进行加标回收试验,回收率在87.0%～90.1%之间,测定值的相对标准偏差(n=7)在3.7%～4.2%之间。     

高效液相色谱法测定农药中三氟氯菊酸的含量

提出了高效液相色谱法测定农药中三氟氯菊酸含量的方法。样品以甲醇超声提取,所得提取液以Agilent Eclipse XDB-C18色谱柱为分离柱,以甲醇与磷酸(0.5+99.5)溶液以体积比55比45组成的混合液为流动相,在检测波长230nm处进行测定。三氟氯菊酸质量浓度在0.025~0.5g·L-1范围内与其峰面积呈线性关系,方法检出限(3S/N)为0.112mg·L-1。加标回收率在97.5%~98.1%之间,测定值的相对标准偏差(n=6)小于2%。     

动态液相微萃取-气相色谱法测定水样中残留有机磷农药

应用动态液相微萃取与气相色谱联用技术测定了水样中3种有机磷农药(敌敌畏、甲基对硫磷、对硫磷).考察了萃取溶剂、溶剂体积、萃取次数、水样pH值以及离子强度对液相微萃取的影响.该方法甲基对硫磷、对硫磷的线性范围在30～70μg·L-1之间,敌敌畏的线性范围在40～70μg·L-1之间,回收率在84.9%～103.0%之间,相对标准偏差(n=7)在5.1%～9.4%之间,检出限(3S/N)为26.5～35.7μg·L-1.     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Synthesis of tetrabenzoporphins of the basis of isoindoline

Chemistry of Heterocyclic Compounds -