顶空-气相色谱-质谱法测定地表水和废水中55种挥发性有机物含量

采用顶空-气相色谱-质谱法测定地表水和废水中55种挥发性有机物的含量。选择顶空平衡温度和时间分别为65℃和50min。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和选择离子监测模式。以氟苯和1,2-二氯苯-D4为内标物。55种挥发性有机物的线性范围均为10.0~400μg·L-1。全扫描模式下,检出限在0.8~6.8μg·L-1之间,加标回收率在81.3%~116%之间,测定值的相对标准偏差(n=6)在0.40%~15%之间。在选择离子监测模式下,检出限在0.2~1.1μg·L-1之间,加标回收率在81.0%~117%之间,测定值的相对标准偏差(n=6)在0.40%~6.5%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。     

QuEChERS-超高效液相色谱-串联质谱法快速测定鱼肉中22种磺胺类药物残留

结合QuEChERS前处理技术,提出了测定鱼肉中22种磺胺类残留的超高效液相色谱-串联质谱法。样品用含0.1%(体积分数,下同)甲酸的乙腈溶液提取后,经QuEChERS试剂盒净化。净化液在Agilent ZORBAX Eclipse Plus C18色谱柱上分离,以0.1%甲酸溶液-甲醇为流动相进行梯度洗脱。采用电喷雾正离子源及计划式多反应监测模式进行测定,以内标法定量。磺胺硝苯、磺胺、磺胺喹噁啉的线性范围为0.5~50μg·L-1,检出限(3S/N)为0.5μg·L-1;其他19种磺胺类兽药的线性范围为0.1~50μg·L-1,检出限(3S/N)为0.1μg·L-1。加标回收率在78.2%~118%之间,测定值的相对标准偏差(n=6)在3.4%~19%之间。方法用于鱼肉中多种磺胺类药物残留的快速测定,结果与标准方法测定结果一致。     

快速溶剂萃取-气相色谱-串联质谱法测定血中12种催眠类药物

提出了气相色谱-串联质谱法测定血液中12种催眠类药物含量的方法。样品以乙酸乙酯-环己烷-丙酮(2+2+1)混合液为萃取剂,使用氧化铝吸附剂达到在线净化的效果,经快速溶剂萃取仪提取后,提取液用氮气吹干,用甲醇0.5mL溶解,通过VF-5MS色谱柱分离,采用电子轰击离子源多反应监测模式进行测定。12种催眠类药物的质量浓度与其峰面积均在50.0~1 000μg·L-1之间呈线性关系,测定下限(10S/N)在0.02~4.7μg·L-1之间。加标回收率在65.4%~98.2%之间,测定值的相对标准偏差在0.9%~14.8%之间。     

离子液体双水相萃取-高效液相色谱-串联质谱法测定尿液中溴鼠灵

提出了离子液体双水相萃取-高效液相色谱-串联质谱法测定尿液中溴鼠灵。采用亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸盐和磷酸二氢钠组成的双水相体系对样品进行萃取。萃取液在XDB C18色谱柱上分离,以甲醇-0.2%(φ)乙酸(85+15)混合溶液为流动相进行洗脱。采用电喷雾电离-多反应监测模式测定。溴鼠灵的线性范围为0.02~2.0μg·L-1,测定下限(10S/N)为0.015μg·L-1。空白尿样的加标回收率在86.8%~92.5%之间,测定值的日内、日间相对标准偏差(n=6)分别为3.3%~8.1%,6.2%~9.7%。方法可应用于尿液中溴鼠灵的测定。     

高效液相色谱-串联质谱法同时测定配合饲料中维生素B_1和维生素B_2

采用高效液相色谱-串联质谱法同时测定配合饲料中维生素B1和维生素B2。样品经20mmol·L-1甲酸铵溶液提取后,采用Tigerkin C8色谱柱分离,以甲醇-20mmol·L-1甲酸溶液为流动相进行梯度洗脱,采用电喷雾正离子源-选择多反应监测模式检测,外标法定量。维生素B1和维生素B2的质量分数在20.0~500μg·kg-1范围内与其峰面积呈线性关系,检出限(3S/N)均为50μg·kg-1。对虾饲料进行加标回收试验,回收率在88.0%~120%之间,测定值的相对标准偏差(n=6)为0.90%~2.7%。方法已应用于市售配合饲料中维生素B1和维生素B2的测定。     

超高效液相色谱-串联质谱法测定畜产品中6种青霉素类药物残留

采用超高效液相色谱-串联质谱法快速测定牛肉和牛奶中青霉素类药物残留。样品以磷酸盐缓冲溶液提取、乙酸锌沉淀蛋白、正己烷脱脂,然后经HLB固相萃取柱净化后,采用超高效液相色谱-串联质谱分离检测,外标法定量。6种青霉素的线性范围均在25.0μg·L-1以内,检出限(3S/N)为2μg·kg-1,测定下限(10S/N)为5μg·kg-1。加标回收率在77.0%~99.8%之间,测定值的相对标准偏差(n=6)在3.7%~13%之间。     

高效液相色谱-串联质谱法测定农产品中矮壮素残留量

提出了农产品中矮壮素的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品经甲醇-水(1+1)溶液提取,正己烷液液萃取后,采用阳离子交换固相萃取柱净化。所得净化液以阳离子交换树脂与C18混合填料色谱柱为固定相,以含0.1%(体积分数)乙酸的乙腈-10mmol·L-1乙酸铵(1+1)溶液为流动相进行等度洗脱,采用电喷雾正离子源,多反应监测模式检测,同位素内标法定量。矮壮素的线性范围为1.0~100μg·L-1,检出限(3S/N)为5μg·kg-1,测定下限(10S/N)为10μg·kg-1。矮壮素在10,100,500μg·kg-1等3个加标水平的回收率为90.5%~98.5%之间,测定值的相对标准偏差(n=6)在0.99%~2.2%之间。     

液相色谱-串联质联法测定食品用塑料包装中邻苯二甲酸酯类增塑剂

采用液相色谱-串联质谱法(LC-MS/MS)测定了食品用塑料包装材料中的3种邻苯二甲酸酯(DBP、BBP、DEHP)的含量。样品经正己烷超声提取后,以Hypersil Gold色谱柱为固定相,以甲醇-水(95+5)溶液为流动相进行洗脱,采用电喷雾正离子源-多反应检测模式检测。3种邻苯二甲酸酯的质量浓度在5.00~250μg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.1~0.2μg·L-1之间。对空白样品进行加标回收试验,回收率在92.5%~101%之间,测定值的相对标准偏差(n=6)在4.6%~6.9%之间。     

高效液相色谱-串联质谱法测定腐竹中乌洛托品残留量

采用高效液相色谱-串联质谱法测定腐竹中乌洛托品的残留量。样品经乙腈超声提取,正己烷去脂。以Kinetex HILIC 100A色谱柱为分离柱,以不同体积比的10mmol·L-1甲酸铵氨水缓冲溶液和乙腈混合液为流动相进行梯度洗脱,采用电喷雾正离子多反应监测模式检测。乌洛托品的质量分数在5~100μg·kg-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.3μg·kg-1。以空白样品为基体进行加标回收试验,所得回收率在96.6%~97.5%之间,测定值的相对标准偏差(n=6)在3.9%~7.6%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.     

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.     

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。     

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.     

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.

     

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。     

Investigation of Kinetics of Solid-Phase Synthesis of Lithium Orthosilicate

The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m²g^-1 instead of aerosil with one of 175 m²g^-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended. This revised version was published online in July 2006 with corrections to the Cover Date.     

小环化合物中饱和碳质子化学位移的计算

小环化合物由于其张力、构型、构象和各向异性效应等原因,环碳上质子化学位移缺乏规律性,难以预测,对此作者曾提出一种近似算法。本文根据303种小环化合物中饱和碳质子的化学位移实验数据,将适于计算这类质子化学位移的公式表述为:     

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。