气相色谱-串联质谱法测定茶叶中24种农药残留量

采用气相色谱-串联质谱法测定茶叶中24种农药残留量。茶叶样品经乙腈超声振荡提取,Cleanert TPT固相萃取柱净化,乙腈-甲苯(3+1)溶液洗脱。在气相色谱分离中用RTX-5MS色谱柱为固定相,在质谱分析中采用多反应监测模式。采用内标法定量,24种农药的线性范围均为0.005~1.0mg·L-1,检出限(3S/N)在0.2~1.2μg·kg-1之间。在0.01,0.1,1.0mg·kg-1等3个浓度水平进行加标回收试验,回收率在67.5%~122%之间,测定值的相对标准偏差(n=6)在0.60%~9.9%之间。     

气相色谱-质谱法测定聚氨酯胶粘剂中二异氰酸酯

采用气相色谱-质谱法测定聚氨酯胶粘剂中的二异氰酸酯的含量。样品经乙酸乙酯超声提取15min。在气相色谱分离中用HP-5色谱柱为固定相,在质谱分析中采用全扫描和选择离子监测模式。二异氰酸酯在一定的质量浓度范围内与其峰面积呈线性关系,方法的测定下限(10S/N)在5~100 mg·kg-1之间。以空白样品为基体进行加标回收试验,所得回收率在60.8%~97.5%之间,测定值的相对标准偏差(n=6)在0.67%~7.1%之间。     

液液萃取-气相色谱-质谱法测定墨水中的16种多环芳烃

采用液液萃取-气相色谱-质谱法测定墨水中的16种多环芳烃。样品经二氯甲烷液液萃取后,使用固相萃取技术进行纯化。在气相色谱分离中用DB-5MS色谱柱为固定相,在质谱分析中采用选择离子监测模式。16种多环芳烃在一定的质量浓度范围内与其峰面积呈线性关系,方法的检出限(3S/N)在5.0~30μg·kg-1之间。以空白样品为基体进行加标回收试验,所得回收率在60.6%~116%之间,测定值的相对标准偏差(n=6)在1.5%~5.3%之间。     

气相色谱-串联质谱法测定蔬菜和土壤中17种邻苯二甲酸酯

采用气相色谱-串联质谱法测定蔬菜和土壤中17种邻苯二甲酸酯的含量。蔬菜样品用乙腈均质提取,土壤利用水和乙腈振荡提取。在气相色谱分离中用DB-1701MS色谱柱为固定相,在质谱分析中采用多反应监测模式。17种邻苯二甲酸酯的质量浓度均在2.00~500μg·L-1范围内与其峰面积呈线性关系,测定下限(10S/N)在0.01~0.32μg·kg-1之间。以空白样品为基体进行加标回收试验,所得回收率在71.1%~118%之间,测定值的相对标准偏差(n=6)在0.20%~15%之间。     

气相色谱-质谱法测定空气中8种挥发性酚类化合物的含量

提出了气相色谱-质谱法测定空气中8种挥发性酚类化合物含量的方法。空气样品采用硅胶吸附管采集,丙酮淋洗解吸。在气相色谱分离中用HP-VOC色谱柱为固定相,在质谱分析中采用选择离子监测模式。采用内标法定量。8种挥发性酚类化合物的线性范围均为0.20~10.0mg·L-1,检出限在1.5~5.2μg·m-3之间。以空白样品为基体进行加标回收试验,所得回收率在80.4%~86.7%之间,测定值的相对标准偏差(n=5)在1.7%~3.9%之间。     

固相萃取–气相色谱–串联质谱法测定茶叶中9种农药残留量

建立固相萃取净化–气相色谱–串联质谱法同时测定茶叶中9种农药残留量的方法。茶叶样品用乙腈均质提取,提取液经固相萃取净化处理后,采用DB–5MS毛细管色谱柱分离,在多反应监测模式下测定,外标法定量。9种农药组分的质量浓度在0.01~0.50 mg/L范围内与其色谱峰面积呈良好线性,相关系数r~2大于0.998,方法测定下限(10 S/N)为0.002~0.01 mg/kg。以空白绿茶、红茶、普洱茶和乌龙茶为基体,在0.05,0.1,0.2 mg/kg 3个添加水平进行加标回收试验,加标回收率在73.6%~99.7%之间,相对标准偏差为4.2%~8.7%(n=6)。该法操作简便、快速,适用于茶叶中多种农药残留的测定。     

液液萃取分离-气相色谱-串联质谱法同时测定水中12种有机氯农药

采用液液萃取分离-气相色谱-串联质谱法同时测定水中12种有机氯农药的含量。样品经正己烷提取,在气相色谱分离中用DB-5MS色谱柱为固定相,在质谱分析中采用多反应监测模式。12种有机氯农药在一定的质量浓度范围内与其峰面积呈线性关系,方法的检出限在0.002~0.032μg·L~(-1)之间,测定下限在0.008~0.128μg·L~(-1)之间。以空白样品为基体进行加标回收试验,所得回收率在99.1%~126%之间,测定值的相对标准偏差(n=7)在2.3%~9.3%之间。     

固相微萃取-气相色谱-质谱法测定橡胶密封圈中8种N-亚硝胺含量

采用固相微萃取-气相色谱-质谱法测定橡胶密封圈中8种N-亚硝胺的含量。按国家标准GB/T 24153-2009进行样品的预处理,然后用二乙烯基苯/聚二甲基硅氧烷萃取头,在30℃和800r·min~(-1)转速的条件下萃取45min。在气相色谱分离中用Agilent 1701色谱柱为固定相;在质谱测定中采用选择离子监测模式。8种N-亚硝胺的线性范围均为0.10~2.0mg·L~(-1),方法的检出限(3S/N)均为0.03mg·kg~(-1)。以空白样品为基体进行加标回收试验,回收率在73.0%~96.1%之间,测定值的相对标准偏差(n=6)在1.3%~9.7%之间。     

吹扫捕集-气相色谱-质谱法测定水中丁基黄原酸及27种挥发性有机物

采用吹扫捕集-气相色谱-质谱法测定水中丁基黄原酸及27种挥发性有机物的含量。样品经盐酸(1+1)溶液调节酸度,在气相色谱分离中用HP-VOC毛细管色谱柱为固定相,在质谱分析中采用全扫描和选择离子监测模式。采用内标法定量。28种化合物的检出限在0.10~6.93μg·L~(-1)之间。加标回收率在96.9%~110%之间,测定值的相对标准偏差(n=6)在0.92%~11%之间。     

预浓缩-气相色谱-质谱法测定大气中34种挥发性有机物含量

采用预浓缩-气相色谱-质谱法测定大气中34种挥发性有机物的含量。采用苏玛罐采集大气样品,通过预浓缩系统富集浓缩,在气相色谱分离中用DB-624色谱柱为固定相,在质谱分析中采用全扫描模式。34种挥发性有机物的线性范围均为0.5~40nL·L-1,方法的检出限在0.01~0.14μg·m-3之间。回收率在86.7%~98.7%之间,测定值的相对标准偏差(n=6)在2.5%~8.6%之间。     

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.     

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.     

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^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。