高效液相色谱法同时测定环境水体中的双酚A、辛基酚和壬基酚

建立了高效液相色谱-荧光检测法同时测定环境水体中双酚A(BPA)、辛基酚(DP)和壬基酚(NP)的方法。比较了液液萃取(LLE)和固相萃取(SPE)两种前处理方法,并设计了供复杂样品使用的净化柱。水样经萃取后,用轻柔氮气吹干,甲醇溶解,采用Phenomenex Luna C18色谱柱,以乙腈-水为流动相进行梯度洗脱,在激发波长275nm、发射波长300nm下进行荧光检测。结果表明,BPA、NP、OP的仪器检出限(S/N=3)分别为1μg/L、2μg/L和1μg/L。SPE法操作简单快捷,虽然NP、OP的回收率低于LLE法,但仍能满足对环境样品的测定要求。净化柱净化效果较好,能够进一步去除基质干扰,满足特别复杂水样的前处理。方法基于不同样品处理的浓缩倍数不同,三种物质的检出限在0.001～0.004μg/L之间。环境水样中BPA、NP和OP的加标回收率分别为86.2%～104%、61.6%～109%和81.5%～100%,相对标准偏差(RSD)分别为2.9%～6.4%、2.4%～5.6%和2.7%～6.9%。     

基质固相分散-气相色谱串联质谱法测定孕妇血清中22种持久性有机污染物

建立了基质固相分散技术-气相色谱串联质谱法(MSPD-GC-QQQ-MS/MS)同时测定孕妇血清中22种持久性有机污染物(艾氏剂、狄氏剂、七氯、灭蚁灵、六六六、多氯联苯和滴滴涕)的方法.血清样品与C18吸附剂混合净化,正己烷溶液洗脱,GC-QQQ-MS/MS测定.采用Agilent J&W DB-35ms (30 m×0.25 mm×0.25 μm)分离,正电子离子源(EI+)模式电离,多反应监测模式(MRM)下进行测定,外标法定量.结果表明,在1.0～1000.0 ng/mL的范围内,22种持久性有机污染物的相关系数均大于0.99;在2.0和20.0 ng/mL的添加水平下,所有持久性有机污染物回收率均在75％～ 115％之间,方法定量限均≤0.15 ng/mL.在比较基质固相分散(MSPD)、液液萃取(LLE)和固相萃取(SPE)提取和净化实际加标血清样品时,MSPD方法的结果中位数更接近真实值,且离散程度最小.本方法适用于人类血清中多种持久性有机物的定性和定量分析.     

分散液液微萃取-数码比色法测定水样中痕量钒

研究了分散液液微萃取-数码比色法测定水样中的痕量钒. 在酸性介质中, 痕量钒(V)和N-苯甲酰-N-苯基羟胺(BPHA)作用, 生成紫红色螯合物, 用乙醇做分散剂, 以三氯甲烷为萃取剂进行分散液液微萃取, 萃取液点样在薄层硅胶板上用数码相机进行数码成像. 成像斑点的灰度值和钒(V)的浓度成正比, 据此建立了测定水样中痕量钒的新方法. 对影响萃取富集效率和数码成像效果的因素进行了优化. 钒(V)浓度在5.0～400 μg•L－1范围内有良好的线性关系(r＝0.9993), 检出限为0.87 μg•L－1. 方法已应用于实际水样分析, 加标回收率在97.4%～102.7%之间, 相对标准偏差在1.7%～3.3%之间. 方法具有仪器成本低、方便快速、灵敏度高、环境友好等特点, 可满足野外现场的检测要求.     

分散液液微萃取-数码比色法测定环境及生物样品中亚硝酸根

研究了分散液液微萃取(DLLME)-数码比色(DC)法测定水样中的亚硝酸根.在酸性介质中,亚硝酸根和对硝基苯胺及二苯胺作用,生成红色偶氮化合物.用乙醇作分散剂,以四氯化碳为萃取剂进行分散液液微萃取,萃取液点样在薄层硅胶板上用数码相机进行数码成像.成像斑点的灰度值和亚硝酸根的浓度成正比,据此建立了测定水样中痕量亚硝酸根的新方法.对影响萃取富集效率和数码成像效果的因素进行了优化.亚硝酸根浓度在2.0～80 μg/L范围内有良好的线性关系(r=0.9997);检出限为0.22 μg/L.方法已应用于实际水样及人体体液分析,加标回收率在97.6%～103.4%之间,相对标准偏差在1.7%～3.4%之间;方法具有仪器成本低、方便快速、灵敏度高、环境友好等特点,可满足野外现场的检测要求.     

离子液体-分散液液微萃取-比色法测定水样中痕量铁

建立了基于分散液液微萃取(DLLME)-数字成像比色(DIC)法测定水样中Fe的方法。在乙酸-乙酸钠缓冲溶液中,Fe(Ⅲ)被盐酸羟胺还原成Fe(Ⅱ)后与邻菲罗啉作用生成橙红色络合物。以离子液体[C6M IM][PF6]为萃取剂,乙腈为分散剂,采用涡旋辅助的分散液液微萃取方法对该络合物进行萃取和富集后,直接通过手机比色装置对Fe进行测定。优化了手机比色装置参数和分散液液微萃取的萃取剂种类及用量、分散剂种类及用量等条件。结果表明,在最佳条件下,方法的线性范围为24～200μg/L,相关系数(r~2)为0.9973,检出限为3μg/L,加标回收率为90.0%～108.0%,相对标准偏差(RSD)为0.8%～1.8%。该方法可用于测定环境水样中痕量Fe。     

固相萃取-气相色谱质谱法检测水体中典型有机磷酸酯阻燃剂

建立了固相萃取(SPE)与气相色谱质谱(GC-MS)联用测定自然水体中8种有机磷酸酯阻燃剂(OPFRs)OPFRs的分析方法。通过对GC MS条件与SPE萃取条件的优化,采用Poly-Sery PSD固相萃取小柱对水样进行富集浓缩,用4 mL乙酸乙酯洗脱,以选择离子扫描方式对目标物进行定性和定量分析,并采用内标法定量。本方法在对应OPFRs线性范围内的线性相关系数为0.9937～0.9995;检出限为0.006～0.850 ng/L;定量限为0.015～2.0 ng/L。除磷酸三(2-乙基)己基酯(TEHP)外,其它OPFRs的加标回收率为70.3%～114.3%。TEHP加标10和50 ng/L时,回收率为64.0%～69.3%;加标100 ng/L时回收率为34.3%。将本方法应用于太湖梅梁湾水体中OPFRs分析,其总浓度值为1000～2700 ng/L。     

凝固漂浮有机液滴-分散液液微萃取结合高效液相色谱法同时测定地表水中多环芳烃和酞酸酯

多环芳烃和酞酸酯是国际公认的优控污染物,因此准确快速地测定水中多环芳烃和酞酸酯非常重要。凝固漂浮有机液滴-分散液液微萃取(DLLME-SFO)是一种简便、快速、环境友好、灵敏度高的样品前处理技术。采用DLLME-SFO同时测定地表水中多环芳烃和酞酸酯的分析方法鲜有报道。该文采用凝固漂浮有机液滴-分散液液微萃取富集技术,结合高效液相色谱紫外/荧光法,建立了同时测定地表水中16种多环芳烃和6种酞酸酯的分析方法。考察优化了影响萃取效率的主要因素,包括萃取剂的种类和用量、分散剂的种类和用量、萃取时间和离子强度等。优化后的萃取实验条件为:5.0 mL水样,10μL十二醇为萃取溶剂,500μL甲醇为分散溶剂,涡旋振荡时间2 min,氯化钠用量0.2 g。目标化合物经多环芳烃专用色谱柱(SUPELCOSIL^TM LC-PAH, 150 mm×4.6 mm, 5μm)结合乙腈-水梯度洗脱分离,16种多环芳烃除苊烯外采用荧光检测,苊烯和6种酞酸酯采用紫外检测,外标法定量。结果表明,22种目标化合物的基质加标回收率为60.2%～113.5%,相对标准偏差为1.9%～14.3%;多环芳...     

分散液相微萃取-气相色谱联用分析水样中菊酯类农药残留

将分散液-液微萃取(DLLME)与气相色谱-电子俘获检测(GC-ECD)技术相结合,建立了高灵敏度测定水样中7种菊酯类农药残留的新方法。对影响萃取富集效率的因素进行优化,萃取条件选定为:在5.0mL样品溶液中加入10.0μL氯苯和1.0mL丙酮,分散混匀后,以5000r/min离心5min,吸出萃取溶剂氯苯直接进样分析。在优化条件下7种菊酯类农药的富集倍数高达708～1087倍。以α-六六六为内标,7种菊酯类农药在0.8～600μg/L范围内具有良好的线性关系,线性相关系数在0.9990～0.9999之间;检出限为0.04～0.10μg/L(S/N=3)。本方法已应用于自来水、井水及河水等实际水样的分析,平均加标回收率在76.0%～116.0%之间;相对标准偏差在3.1%～7.2%之间。方法具有操作简单、富集效率高和灵敏度高等特点,可满足水样中菊酯类农药残留的检测要求。     

液液萃取-气相色谱-质谱法测定水中27种半挥发性有机污染物

采用液液萃取(LLE)法,以二氯甲烷—正己烷(40:60,V:V)混合液对水中7类27种半挥发性有机污染物(SVOCs)进行提取、浓缩前处理,结合气相色谱/质谱(GC-MS)选择离子检测法(SIM)对水中27种SVOCs进行监测分析,实验优选出了分离效果较好的色谱柱VF-1701 ms(30 m×0.25 mm×0.25μm),优化了液液萃取及GC-MS的分析条件,建立了水样中7类27种SVOCs的LLE-GC-MS/SIM分析方法,试样各组分曲线相关系数R~2均大于0.9981,检出限为0.021~0.250μg/L,平均加标回收率为75.5%~116.3%,相对标准偏差(RSD)为5.2%~15%,与《生活饮用水卫生检验标准标准农药指标》(GB/T 5750.9-2006)相比,除五氯酚单独反萃取外,该法无需对其余26种SVOCs分类进行前处理。     

高效液相色谱-串联质谱法对水环境中微量磺胺、大环内酯类抗生素、甲氧苄胺嘧啶与氯霉素的检测

应用固相萃取(SPE)及液相色谱-电喷雾串联质谱(LC-ESI MS/MS)技术,建立了水体中微量磺胺、大环内酯类抗生素、甲氧苄胺嘧啶及氯霉素的定量分析方法.水样中的抗生素通过HLB萃取小柱富集后,以C18反相柱为分析柱,甲醇、醋酸铵和0.1%甲酸混合溶液为流动相,采用LC-MS/MS进行定量分析.选择电喷雾正电离?ESI+),多反应监测模式(MRM),内标法定量.海水和城市污水中抗生素的方法定量下限分别为1.1 ～34.7 ng/L和2.5 ～57.2 ng/L,平均回收率分别为78% ～98%、67% ～111%,相对标准偏差不高于8.8%.通过该方法初步分析了海水及污水中抗生素的含量,检出多种磺胺和大环内酯类抗生素.     

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。     

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.     

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.     

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。     

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.     

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。