液-液萃取富集-气相色谱法测定水中有机氯农药和多氯联苯

采用正己烷作萃取溶剂提取并富集水样中有机氯农药(OCP's)和多氯联苯(PCB's),所得提取液经浓缩至约0.5mL并定容至1.0mL后,用气相色谱法-电子捕获检测器测定水中有机氯农药和多氯联苯。采用Rtx-5MS和Rtx-1701双柱法根据与标准物质的保留时间相对比进行定性分析;采用Rtx-5MS柱对被测组分按外标法进行定量分析。结果表明:各种农药质量浓度均在0.5～40μg·L~(-1)范围内与峰面积呈线性关系。有机氯农药和多氯联苯的检出限(3s)在0.001 1～0.004 7μg·L~(-1)之间。用标准加入法测得其回收率在83.3%～112.1%之间,相对标准偏差(n=7)在4.4%～9.4%之间。     

分散液液微萃取-气相色谱/质谱法测定水中多环芳烃

用分散液液微萃取-气相色谱/质谱法测定水样中的16种多环芳烃(PAHs)。通过实验确定最佳萃取条件为:20μL四氯化碳作萃取剂,1.0 mL乙腈作分散剂,超声萃取1 min。在优化条件下,多环芳烃的富集倍数达到216～511,方法在0.05～50μg/L范围内呈良好的线性关系,相关系数(R2)在0.9873～0.9983之间,检出限为0.0020～0.14μg/L。相对标准偏差(RSD)在3.82%～12.45%(n=6)之间。该方法成功用于实际水样中痕量多环芳烃的测定。     

液液萃取-气相色谱/质谱法同时测定水中3种季胺盐化合物

建立了液液萃取-气相色谱/质谱同时测定水中3种典型季胺盐化合物十二烷基三甲基氯化铵(DTAC)、十六烷基三甲基溴化铵(CTAB)、双十二烷基二甲基氯化铵(DDAC)的分析方法。采用电子轰击(EI)-选择离子模式(SIM)进行定性与定量分析,DTAC和CTAB的特征离子为m/z 58,DDAC的特征离子为m/z 212。考察了萃取剂种类、萃取次数、pH值以及盐度对萃取效率的影响。以HCl及30%NaCl溶液调节水样pH值为1.5及盐度为3%,以5 mL三氯甲烷萃取2次,3种目标化合物的线性范围在0.01~2.0 mg/L之间,检出限LOD(S/N=3)为2.5~8.5μg/L。以此方法测定自来水、湖水、河水、选矿废水样品,3种目标化合物的含量在0.06~2.45 mg/L之间,不同加标水平(0.2,0.5和1.0 mg/L)回收率在65%~113%之间,相对标准偏差在3.8%~23.0%之间。     

分散液液微萃取/气相色谱-质谱法测定水中多氯联苯

为了快速准确的测定水中多种多氯联苯(Polychlorinated Biphenyls, PCBs),建立了分散液液微萃取(Dispersive Liquid-Liquid Microextraction, DLLME)与气相色谱-质谱联用,快速测定水中20种PCBs的新方法。方法以二氯甲烷(20μL)为萃取剂,丙酮(1.0 mL)为分散剂,混匀后注入10.0 mL水样中,以4℃、8 000 r/min离心10 min,吸取下层有机相10μL,加入0.2μL内标后进样分析。结果表明,在最佳条件下,20种PCBs能够被充分提取和良好分离。在10.0～500μg/L浓度范围内呈现良好的线性关系,线性相关系数为0.999,检出限为0.7～1.8μg/L。对水样进行20、100、450μg/L的加标实验,相对标准偏差与回收率分别在1.6%～9.7%与72.0%～115%之间,能够满足环境水样中PCBs的测定要求。     

分散液液微萃取-气相色谱-质谱法测定鱼塘水中24种农药

采用分散液液微萃取结合气相色谱-质谱法同时快速测定鱼塘水中24种常见农药。在水样5.00mL中快速加入乙醇1.0mL、四氯乙烯30μL,形成乳浊液,静置5min后,以4 000r·min~(-1)转速离心5min,有机相在VF-5MS毛细管色谱柱上分离,质谱分析中选择电子轰击离子源和选择离子监测模式。24种农药的质量浓度在一定范围内与峰面积呈线性关系,检出限(3S/N)在0.33~7.45μg·L~(-1)之间。加标回收率在72.4%~103%之间,测定值的相对标准偏差(n=6)在1.7%~13%之间。该方法成功应用于鱼塘投毒案件中硫丹α、硫丹β和甲氰菊酯的检测。     

顶空液液萃取-气相色谱-质谱法用于白术挥发性成分的分析

采用高温顶空液相萃取再转移的方法,对中药白术中挥发性成分进行萃取分离富集,采用顶空液液萃取/气相色谱-质谱(HS-LP-LPE/GC-MS)联用法进行测定,并与传统水蒸汽蒸馏法(SD)提取的挥发性成分进行对比。对各种测定条件和影响因素进行了考察,最佳萃取条件为:1.0 mL PEG 400为高温萃取剂,样品用量1.2 g,萃取温度120℃,萃取时间60 min,再将萃取剂用1.0 mL正己烷进行反萃取后进行GC-MS分析;采用HS-LP-LPE/GC-MS鉴定了33个组分,占总组分含量93.18%;SD鉴定了31个组分,占总组分含量97.12%。两种方法共同检测到的组分有29个,均以苍术酮(Atractylone)含量最高。结果表明,两种方法所提取的组分基本相同,可用于白术挥发性成分的测定。     

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。     

低温富集液液萃取-气相色谱-串联质谱法测定水样中15种农药残留

利用低温冷冻条件下农药在水相和有机相之间达到新的传质平衡,建立了低温富集液液萃取-气相色谱-三重四极杆串联质谱法同时测定水样中15种有机磷、有机氯及菊酯类农药的方法。通过对样品前处理中的溶剂选择、冷冻温度及冷冻时间的优化,最终确定的样品前处理条件为:萃取溶剂为甲苯2.0 mL;冷冻温度-40℃;冷冻时间1h。15种农药的检出限(3S/N)在0.005~0.02μg·L-1范围,测定下限(10S/N)为0.02~0.07μg·L-1。方法用于水样中农药的分析,加标回收率在78.8%~124%之间,测定值的相对标准偏差(n=5)在0.9%~9.1%之间。     

离子液体分散液液微萃取-水相固化-高效液相色谱法测定食用菌中3种拟除虫菊酯类农药的残留量

粉碎匀浆后的食用菌样品用乙腈涡旋提取。提取液与离子液体1-己基-3-甲基咪唑六氟磷酸盐混合后注入5mL水中,再加入50mg的氯化钠,完成分散液液微萃取。离心后离子液体沉于离心管底部,取出水相中大部分水,将离心管放置于-20℃冰箱中,待上层水相固化后,取出底部全部的离子液体,用甲醇稀释。采用高效液相色谱法测定稀释液中3种拟除虫菊酯类农药的残留量。以Eclipse Plus C_(18)色谱柱为分离柱,以95%(体积分数)乙腈溶液为流动相,在测定波长230nm处进行测定。3种拟除虫菊酯类农药的质量分数均在50～5 000μg·kg~(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)为1.0～1.4μg·kg~(-1),测定下限(10S/N)为3.2～4.7μg·kg~(-1)。以空白样品为基体进行加标回收试验,所得回收率为71.6%～92.7%,测定值的相对标准偏差(n=5)为0.050%～6.6%。     

分散液液微萃取-气相色谱-质谱法测定水中环氧七氯

向已加入100mg氯化钠的5.0mL水样中加入由20.0μL四氯乙烯、1.0mL丙酮混合而成的分散微萃取溶液,采用气相色谱-质谱法测定萃取相中环氧七氯的含量。在气相色谱分离中采用DB-5ms石英毛细管色谱柱,在质谱分析中采用选择离子监测模式。环氧七氯的质量浓度在0.5～200μg·L~(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)为0.1μg·L~(-1)。以空白样品为基体进行加标回收试验,所得回收率为81.6%～97.4%,测定值的相对标准偏差(n=5)为4.6%～7.2%。     

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。