固相萃取-毛细管柱-气相色谱法测定水中11种有机磷农药

提出了固相萃取分离-毛细管柱-气相色谱法测定水中11种有机磷农药的方法。水样经Waters oasis HLB固相萃取小柱分离并净化,甲醇-丙酮(70+30)混合液洗脱。用Varian cp-sil24CB色谱柱(30m×0.25mm,0.25μm)分离,脉冲火焰光度检测器检测。11种有机磷农药的质量浓度均在5.00μg·L-1以内与其峰面积呈线性关系,测定下限(10S/N)在0.03~0.05μg·L-1之间。方法用于地表水样和饮用水样分析,加标回收率在65.7%~124%之间,测定值的相对标准偏差(n=6)在1.8%~9.9%之间。     

分散液液微萃取-气相色谱-质谱法测定鱼塘水中24种农药

采用分散液液微萃取结合气相色谱-质谱法同时快速测定鱼塘水中24种常见农药。在水样5.00mL中快速加入乙醇1.0mL、四氯乙烯30μL,形成乳浊液,静置5min后,以4 000r·min~(-1)转速离心5min,有机相在VF-5MS毛细管色谱柱上分离,质谱分析中选择电子轰击离子源和选择离子监测模式。24种农药的质量浓度在一定范围内与峰面积呈线性关系,检出限(3S/N)在0.33~7.45μg·L~(-1)之间。加标回收率在72.4%~103%之间,测定值的相对标准偏差(n=6)在1.7%~13%之间。该方法成功应用于鱼塘投毒案件中硫丹α、硫丹β和甲氰菊酯的检测。     

固相膜萃取-气相色谱法测定养殖用水中痕量有机磷农药

采用固相膜萃取-气相色谱法测定养殖用水中乐果、甲基对硫磷和马拉硫磷等3种有机磷农药的含量。水样经C18固相萃取膜萃取后,用丙酮和二氯甲烷洗脱。用SPB-608毛细管色谱柱分离,氮磷检测器检测。3种有机磷农药的质量浓度均在0.02~1.0μg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.0025~0.004μg·L-1之间。以空白样品为基体进行加标回收试验,回收率在93.0%~111%之间,测定值的相对标准偏差(n=5)在0.13%~5.2%之间。     

固相萃取-高效液相色谱-原子荧光光谱法联用测定水中无机汞(Ⅱ)及有机汞

采用固相萃取-高效液相色谱-原子荧光光谱法联用技术测定了水样中无机汞及有机汞。水样流经以DDTC溶液改性的C18固相萃取小柱。用含有10%(体积分数)乙腈的混合洗脱液4mL,分4次,以1~2mL·min-1流量从小柱上将3种形态的汞洗脱。收集洗脱液,混匀,过滤后通过Venusil MP C18色谱柱,用乙腈、145mmol·L-1乙酸铵溶液和20mmol·L-1半胱氨酸溶液(5+45+50)混合液作为流动相进行色谱分离。根据选定的形态分析条件,用原子荧光光谱法进行测定。汞质量浓度在0.5~20μg·L-1范围内与其峰面积呈线性关系,汞(Ⅱ)、甲基汞、乙基汞的检出限(3S/N)依次为1.6,0.5,1.2ng·L-1。加标回收率在71.2%~95.2%之间,测定值的相对标准偏差(n=6)在4.9%~10%之间。     

快速阳极化不锈钢丝固相微萃取-高效液相色谱法测定水中苯并[a]芘含量

采用快速阳极氧化不锈钢丝作为固相微萃取纤维-高效液相色谱法测定水中苯并[a]芘的含量。结果表明:阳极氧化不锈钢丝制作简单、稳定性好、寿命长。水样用固相微萃取头在30℃和1 000r·min-1搅拌速率下萃取40min,萃取头解吸3min。以C18反相色谱柱为分离柱,以甲醇-水(95+5)混合液为流动相进行色谱分离。在检测波长254nm处进行测定。苯并[a]芘的质量浓度在0.1~100μg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为10.92ng·L-1。在10,50μg·L-1等2个浓度水平进行加标回收试验,回收率在97.9%~110%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。     

分子印迹-基质固相分散-高效液相色谱法测定血液中苯磺酸氨氯地平

采用分子印迹-基质固相分散-高效液相色谱法(MI-MSPD-HPLC)测定血液中痕量苯磺酸氨氯地平。制备苯磺酸氨氯地平分子印迹聚合物,以此为基质固相分散剂与样品混合均匀,风干后装柱,用甲醇洗脱苯磺酸氨氯地平。洗脱液在Inertsil DOS-SP分离柱上分离,以甲醇-乙腈-水(70+22+8)混合液为流动相进行洗脱,检测波长为237nm。氨氯地平的线性范围为1.7~20.0μg·L-1,检出限(3S/N)为0.5μg·L-1,测定下限(10S/N)为1.7μg·L-1。对空白血液样品进行加标回收试验,回收率在91.0%~109%之间,测定值的相对标准偏差(n=5)在3.7%~4.8%之间。方法可用于测定血液中的苯磺酸氨氯地平。     

柱前衍生-固相萃取-高效液相色谱法测定饮用水中草甘膦和氨甲基膦酸

提出了柱前衍生-固相萃取-高效液相色谱法测定饮用水中草甘膦和氨甲基膦酸。水样经9-芴基甲基三氯甲烷衍生和C18固相萃取小柱净化后,洗脱液采用Waters Atlantis T3色谱柱分离,流动相为甲醇-0.02mol·L-1乙酸铵溶液(60+40),荧光检测器激发波长为266nm,发射波长为315nm。草甘膦和氨甲基膦酸的质量浓度在5.00~500μg·L-1范围内与其峰面积呈线性关系,检出限均为0.002μg·L-1。对水样进行加标回收试验,草甘膦和氨甲基膦酸的回收率分别在84.4%~92.0%和87.8%~96.8%之间,相对标准偏差(n=6)分别在1.2%~4.3%和1.1%~4.0%之间。该方法适用于水厂出水水样中草甘膦和氨甲基膦酸的同时测定。     

固相萃取/高效液相色谱法测定水中痕量硝磺草酮

建立了一种固相萃取/高效液相色谱(SPE/HPLC)测定水中痕量硝磺草酮的方法。水样用磷酸调至p H 3.0~4.0,经C18固相萃取柱富集、乙腈-水(1∶1)洗脱后,用HPLC/紫外检测器测定。测定条件为:流动相为乙腈-磷酸水溶液(45∶55,p H 3.0),流速0.5 m L/min,色谱柱为Thermo Hypersil-C18柱(250 mm×4.6 mm,5μm),柱温30℃,检测波长233 nm。结果表明:在0.4~20μg·L-1范围内,硝磺草酮的线性良好,方法检出限为0.039μg·L-1。加标浓度为1,5,10μg·L-1时,硝磺草酮的回收率为90.3%~94.7%,相对标准偏差为3.5%~4.6%。应用该方法测得实际水样中硝磺草酮的加标回收率为89.9%~93.2%。该方法具有快速、简便、灵敏等优点,可用于水样中痕量硝磺草酮的测定。     

全自动在线顶空固相微萃取-气相色谱-串联质谱法测定鱼塘投毒案件水样中硫丹和硫丹硫酸酯

鱼塘水样采用全自动在线顶空固相微萃取进行萃取:萃取温度为75℃;萃取时间为60 min;氯化钠加入量为0.3 kgL-1;样品体积为2.0 mL.采用气相色谱-串联质谱法测定水样中硫丹(α-硫丹、β-硫丹)和硫丹硫酸酯的含量,在气相色谱分离中采用DB-5 m s毛细管色谱柱,在串联质谱分析中采用多反应监测模式.α-硫丹...     

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。     

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.     

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.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。