分散固相萃取-气质联用法测定谷物中4种卤代苄腈类除草剂

以新型“镁铝型甲苯-4-磺酸钠柱撑水滑石”材料为吸附剂,建立了测定谷物中4种卤代苄腈类除草剂残留量的分散固相萃取-气质联用法。样品以10%(V/V)甲醇水溶液涡旋提取,离心后上清液以分散固相萃取方式吸附,以稀硫酸溶解吸附剂、用乙酸庚酯萃取4种卤代苄腈类除草剂并以三甲基硅基重氮甲烷衍生化,气质联用法测定,基质匹配校正曲线外标法定量。结果表明：谷物中4种卤代苄腈类除草剂在20, 50, 200μg/kg添加水平的平均回收率为89.7%～99.8%,相对标准偏差为2.0%～5.5%,方法检出限为1.05～5.89μg/kg,定量限为3.49～19.6μg/kg。     

顶空气相色谱-质谱法同时测定蜂蜜中57种挥发性有机溶剂残留

建立了顶空气相色谱-质谱(HS-GC/MS)同时测定蜂蜜中57种挥发性有机溶剂(包括烷烃类、芳香烃类、醇类、酮类、酯类、醚类)残留量的分析方法。蜂蜜样品在密封的顶空瓶中用水溶解后,在顶空仪中于80 ℃下平衡30 min,使气-液两相达到动态平衡。采用DB-624毛细管色谱柱(60 m×0.25 mm×1.40 μm)对57种有机溶剂进行分离,GC/MS测定,外标法定量。该方法对于烷烃类、芳香烃类和醚类挥发性有机溶剂在0.005～0.2 μg、酯类0.05～2.0 μg、酮类0.5～20 μg、醇类2.5～100 μg范围内线性关系良好,相关系数均大于0.996。对于烷烃类、芳香烃类和醚类挥发性有机溶剂在1.0～20 μg/kg、酯类10～200 μg/kg、酮类100～2000 μg/kg、醇类500～10000 μg/kg添加范围内的平均添加回收率为61.0%～113.1%,相对标准偏差为1.9%～9.8%。对于烷烃类、芳香烃类和醚类挥发性有机溶剂的检出限为1.0 μg/kg、酯类10 μg/kg、酮类100 μg/kg、醇类500 μg/kg。该方法操作简单、快速,灵敏度和准确度高,适用于蜂蜜样品中多种挥发性有机溶剂残留量的同时检测。     

分散固相萃取-气相色谱法测定谷物中4种苯甲酸类除草剂EI北大核心CSCD

以新型材料“对甲苯磺酸根-镁铝型水滑石”为分散固相萃取吸附剂,建立了一种同时测定谷物中麦草畏、草灭畏、草芽平和草芽畏4种苯甲酸类除草剂残留量的分散固相萃取-气相色谱法。谷物样品经10%丙酮水溶液涡旋提取、离心,用吸附剂分散固相萃取上清液,经离心、稀硫酸溶解吸附剂、乙醚-乙酸乙酯混合溶液萃取后以三甲基硅基重氮甲烷衍生化,采用气相色谱法测定4种苯甲酸类除草剂,以基质匹配校正曲线外标法定量。结果表明:谷物中4种苯甲酸类除草剂在10~200μg/kg添加水平范围内的平均回收率为84.8%~95.1%,相对标准偏差(RSD)为2.2%~7.2%,方法检出限(LOD)为1.33~3.09μg/kg,定量限(LOQ)为4.42~10.3μg/kg。     

高效液相色谱-串联质谱法测定蔬菜和水果中氟吗啉的残留量

建立了高效液相-串联质谱法(LC-MS/MS)分析蔬菜和水果中氟吗啉残留量检测的方法。通过氟吗啉光照实验,研究了氟吗啉顺反异构体转化规律。以醚菌胺为内标(I.S.),乙酸乙酯提取,经HLB(亲水-疏水净化住)固相萃取小柱净化并富集后,以液相色谱分离,采用质谱正离子多反应监测模式进行定量分析。方法定量限为0.05μg/kg;线性范围为0.05～25μg/kg;提取回收率为77.64%～92.83%;相对标准偏差均小于8.6%。本方法灵敏度高、选择性好,实际样品检测中的检出率达到70%;样品中最高残留量为1.83μg/kg,能满足蔬菜和水果中氟吗啉残留量检测要求。     

土壤中13种磺酰脲类除草剂多残留的超高效液相色谱-串联质谱法测定

建立了超高效液相色谱-串联质谱法同时检测土壤中13种磺酰脲类除草剂多残留量的方法。样品经磷酸缓冲液(pH7.8)-甲醇(体积比1∶1)振荡提取,Oasis HLB固相萃取小柱净化后,采用多反应监测模式测定,外标法定量。13种磺酰脲类除草剂在5～200μg/L范围内线性关系良好,相关系数为0.999 1～0.9999。13种除草剂在5、20μg/kg水平下的平均加标回收率为89%～103%,相对标准偏差为1.1%～11.2%。方法的检出限(S/N=3)为0.020～0.092μg/kg,定量下限(S/N=10)为0.07～0.31μg/kg。     

气相色谱-质谱联用法测定紫菜中扑草净的残留量

建立了固相萃取净化与气相色谱-质谱联用技术测定紫菜中扑草净除草剂残留量的检测方法。样品由乙腈溶剂提取浓缩后,活性炭和氨基柱双柱串联固相萃取净化,由气相色谱-质谱联用技术测定。方法定量限为2μg/kg,满足国外最低10μg/kg的限量要求;方法在10,40和100μg/kg 3个添加水平和不同人员操作条件下,回收率均稳定在90%~120%之间,RSD%≤7.1%。     

分散固相萃取-超高效液相色谱-串联质谱法同时测定蔬菜中10种新烟碱类农药残留

基于分散固相萃取前处理技术,建立了超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定蔬菜中10种新烟碱类农药的检测方法。样品经乙腈提取,NaCl盐析后,提取液经50 mg C₁₈、 50 mg GCB和200 mg PSA净化,在电喷雾正离子多反应监测模式下测定,外标法定量。结果表明,10种农药在0.1～10.0μg/L范围内均呈良好的线性关系,相关系数(r)均大于0.9955,方法检出限为0.5μg/kg,方法定量限为1.0μg/kg。在1, 5和20μg/kg添加水平下,10种农药的平均回收率为73.5%～119.1%,相对标准偏差在0.60%～11%之间。该方法适用于蔬菜中10种新烟碱类农药的批量快速检测。     

两种离子源技术GC/MS法检测蔬菜中多类除草剂的残留量

采用电子轰击(EI)和负化学(NCI)离子源两种离子源技术气相色谱-质谱联用法(GC-MS)测定了蔬菜中10类除草剂的残留量, 并对两种方法进行了比较. 样品经乙腈提取后, 用PSA固相萃取柱净化, 由气相色谱-质谱联用EI或NCI技术进行定量和定性分析. 对含电负性强的除草剂分析, NCI灵敏度高, 在10 ng/g, 20 ng/g和40 ng/g 3个添加水平下的方法回收率为70%～115%, RSD为1.7%～10.1%, 两种离子源技术可以互相补充用于准确检测蔬菜中多类除草剂.     

超声萃取/气相色谱-质谱联用法同时测定皮革及其制品中21种有害有机溶剂的残留量

建立了气相色谱-质谱/选择离子监测方法,对皮革及其制品中21种有害有机溶剂的残留量进行了同时测定。该方法以乙酸乙酯为萃取溶剂,45℃下超声萃取皮革及其制品中残留的有害有机溶剂,萃取液经固相萃取柱净化后进行气相色谱-质谱/选择离子监测法分析,外标法定量。结果表明,在信噪比(S/N)为10的条件下,乙二醇二丁醚(EGDBE)、三乙二醇二甲醚(TEGDME)、二乙二醇单丁醚(DEGBE)和三乙二醇单乙醚(TEGEE)的定量下限均为50μg/kg,N-甲基乙酰胺(MA)和N-甲基甲酰胺(MF)的定量下限均为150μg/kg,甲酰胺的定量下限为300μg/kg,其余14种组分的定量下限均为100μg/kg。在3个不同加标水平下,方法的平均加标回收率为82.1%~94.9%,相对标准偏差(RSD,n=9)为1.6%~4.8%。该方法简单快捷,灵敏度高,可用于皮革及其制品中有害有机溶剂残留量的测定。     

高效液相色谱-串联质谱法快速测定6类食品中增效醚的残留

建立了水果、蔬菜、粮谷、油料、动植物脂类、动物源性食品等6类食品中增效醚残留量快速测定的液相色谱-质谱/质谱(LC-MS/MS)方法。样品盐析并除水后,用三氯甲烷提取,氟罗里硅土填料固相萃取柱净化,丙酮-三氯甲烷混合溶剂洗脱,以乙腈-0.1%甲酸为流动相,在Zobax SB C18液相色谱柱完成分离,并于电喷雾正离子多反应监测模式下质谱测定。考察了提取溶剂、净化方法、柱容量、仪器条件、基质效应对分析结果的影响。增效醚质量浓度在0.5～100μg/L范围内,线性相关系数(r)为0.9976,方法定量限(LOQ)为10μg/kg。17种食品基质添加LOQ、低MRL、2倍MRL、高MRL 4个不同浓度水平时,回收率在80.3%～96.3%之间,相对标准偏差为2.7%～14%,方法可以满足多种食品基质中增效醚残留量的定性和定量检测要求。     

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.     

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。     

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.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

解决能源问题的新途径--光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。