离子色谱-电感耦合等离子体质谱法测定奶粉中的硒形态

采用离子色谱-电感耦合等离子体质谱法测定奶粉中的硒形态。奶粉样品经乙酸沉淀蛋白,流动相提取。选用Hamilton PRP X-100阴离子柱(250mm×4.6mm,5μm),以5mmol·L-1柠檬酸、10mmol·L-1乙酸铵和0.1%(体积分数)三氟乙酸为流动相(pH 5.2),8min内实现了硒酸盐[Se(Ⅵ)]、亚硒酸盐[Se(Ⅳ)]、硒代蛋氨酸(SeMet)和硒代胱氨酸[(SeCys)2]等4种硒形态的基线分离。方法的检出限在0.03~0.10μg·L-1之间。加标回收率在25.0%~105%之间,测定值的相对标准偏差(n=6)在1.8%~7.8%之间。     

微波样品消解-氢化物发生-双通道原子荧光光谱法同时测定家禽内脏中硒和锗

应用氢化物发生-原子荧光光谱法同时测定家禽内脏中的硒和锗含量。采用微波消解法用硝酸和过氧化氢对样品进行消解,以硫脲作为预还原剂,以溶于5g·L-1氢氧化钾溶液中的20g·L-1硼氢化钾溶液作为还原剂。硒、锗的质量浓度均在500μg·L-1范围内与其荧光强度呈线性关系,检出限(3s/k)分别为0.001 08μg·L-1和0.017 1μg·L-1。硒、锗的加标回收率分别在98.9%~102%,97.4%~102%之间。     

氢化物发生-原子荧光光谱法测定北虫草中总硒和无机硒

北虫草试样经硝酸-高氯酸(5+1)混合酸消解,用原子荧光光谱法测定总硒的含量;北虫草试样用盐酸浸提,用原子荧光光谱法测定无机硒的含量。使用溶于5g.L-1氢氧化钾溶液中的20g.L-1硼氢化钾溶液使与溶液中硒离子反应生成氢化物。分析中采用载气及屏蔽气的流量依次为500mL.min-1及1 000mL.min-1。荧光强度与硒的质量浓度在100μg·L-1以内呈线性关系,方法的检出限(3s/k)为0.2μg·L-1。应用此法测定北虫草中硒的含量,总砷测定值的相对标准偏差(n=5)在3.4%～3.9%之间,无机硒的平均回收率为103%。     

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。     

流动注射法同时测定海水中氨氮和磷酸盐

采用流动注射法同时测定海水中氨氮和磷酸盐的含量。在优化的试验条件下,氨氮和磷酸盐的线性范围分别为0.25 mg·L-1和0.30 mg·L-1以内,检出限(3S/N)分别为0.42μg·L-1和0.56μg·L-1。氨氮和磷酸盐加标回收率分别在85.0%~103%和86.7%~103%之间,测定值的相对标准偏差(n=6)分别在0.43%~5.3%和0~4.1%之间。方法用于分析标准物质,测定结果与分光光度法的结果一致。     

膜富集-可见漫反射光谱法测定池塘水和维生素B_(12)药片中痕量钴

1-(2-吡啶偶氮)-2-萘酚与钴离子生成暗绿色的络合物,反应后将其过滤到膜上,测得膜表面漫反射光谱,据此提出了膜富集-可见漫反射光谱法测定池塘水和维生素B12药片中痕量钴的方法。钴的质量浓度在0.2~3.0μg·L-1和3.0~10.0μg·L-1范围内与其吸光度呈线性关系,检出限(3s/k)为0.093μg·L-1。方法用于池塘水和维生素B12药片的分析,加标回收率在96.7%~105%之间,测定值的相对标准偏差在1.4%~2.9%之间。     

静态顶空-气相色谱法测定养殖用水中11种氯苯类化合物

提出了静态顶空-气相色谱法测定养殖用水中11种氯苯类化合物的方法。取10mL含200g·L-1氯化钠的水样在20mL顶空瓶中于70℃振摇30min进行顶空进样的条件优化。选用DB-35MS毛细管气相色谱柱(30m×0.25mm,0.25μm)分离,电子捕获检测器检测,外标法或标准加入法定量。在优化条件下,二氯苯、三氯苯、四氯苯的线性范围分别为0.16~8μg·L-1,0.017 6~0.88μg·L-1,0.004~0.2μg·L-1,五氯苯和六氯苯的线性范围均为0.001~0.05μg·L-1。11种氯苯类化合物检出限(3S/N)为0.0002~0.04μg·L-1,应用此方法对养殖用水进行测定,回收率在86.0%~106%之间,测定值的相对标准偏差(n=5)在2.1%~5.8%之间。     

固相萃取-衍生化-气相色谱-质谱法测定水中类固醇类雌激素

采用固相萃取-衍生化-气相色谱-质谱法同时测定水中4种类固醇类雌激素雌酮(E1)、17β-雌二醇(E2)、17α-乙炔基雌二醇(EE2)、雌三醇(E3)。样品经Oasis HLB固相萃取柱,以丙酮为溶剂进行洗脱后,采用吡啶、N-甲基-N-三甲基硅基三氟乙酰胺于40℃衍生化20min后,采用气相色谱-质谱仪分析。E1、E2、EE2和E3的线性范围分别为5.00~500μg·L-1和10.0~500μg·L-1,4种类固醇类雌激素的检出限(3S/N)在1.5~3.0μg·L-1之间,测定下限(10S/N)在5.0~10μg·L-1之间;方法用于实际水样的分析,加标回收率在86.8%~93.8%之间,测定值的相对标准偏差(n=7)在7.1%~11%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。     

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。     

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。