气相色谱-负化学电离源-飞行时间质谱测定烟草中有机氯农药残留

采用QuEChERS前处理方法,建立了气相色谱-负化学电离源-飞行时间质谱(GC-NCI-TOF-MS)检测烟草中10种有机氯农药残留的分析方法。样品采用乙酸乙酯-正己烷(1 : 1, v/v)溶液提取,提取液经N-丙基乙二胺(PSA)、无水硫酸镁分散固相萃取净化,用GC-NCI-TOF-MS检测分析。根据有机氯化合物特征离子的精确质量数、同位素离子峰簇、碎片离子丰度比和保留时间对目标物定性鉴定,外标法定量。10种有机氯农药的线性关系良好,相关系数 (r²)均大于0.997;相对标准偏差小于6.5%;检出限为0.04~0.80 μ g/kg;加标回收率为77.2%~93.0%。该方法简单快速、灵敏度高、准确性好,适用于烟草中有机氯农药残留的定性分析和定量检测。     

超高效液相色谱-四极杆-飞行时间质谱法快速筛查辣椒粉中27种农药残留

建立了超高效液相色谱-四极杆-飞行时间质谱（UPLC-Q-TOF/MS）快速筛查辣椒粉中27种农药残留的检测方法。样品采用乙腈提取,经Carb/NH₂固相萃取小柱净化,用乙腈-乙酸乙酯（3：1,v/v）洗脱,电喷雾正离子模式检测。在一级质谱模式下,以目标物的保留时间、精确质量数、同位素分布和同位素丰度比定性,以准分子离子峰的峰面积定量。在Targeted MS/MS模式下,通过相应碰撞能量下的离子碎片信息进一步确证。27种化合物在各自的线性范围内线性关系良好,相关系数均大于0.997。27种化合物的定量限为2.5~5.0 μg/kg,在3个添加水平下的回收率为72.3%~118.9%,相对标准偏差（RSD）为0.21%~12.7%（n=6）。该方法快速、灵敏、准确,适用于辣椒粉中多种农药残留的同时检测。     

固相微萃取-气相色谱-质谱法检测30种农药残留

建立使用一种萃取头同时检测蔬菜中30种农药的GC-MS分析方法。采用了SPME-GC/MS自动进样技术,比较聚二甲基硅氧烷(PDMS)、聚丙烯酸酯(PA)、聚二甲基硅氧烷-二乙烯基苯(PDMS/DVB)、聚乙二醇-二乙烯基苯(CW/DVB)4种固定相涂层的分析效果,选择了目标物萃取效率较高、干扰物萃取较少的PDMS。通过正交实验设计,选择不同的萃取温度、萃取时间、振荡速度进行试验,最终确定振荡速度250 r/min,萃取温度70℃,萃取时间60 min作为萃取条件。对不同的无机盐浓度对标准品溶液和加入基质标准品溶液的提取效率的影响分别进行了试验,确定用10%(w/V)NaCl溶液增加提取液离子强度。试验过程中优化分析的色谱条件和质谱条件,进样到分析结束时间可控制在40 min。该方法检测蔬菜样品中混合标准溶液的回收率为43%～119%,相对标准偏差在3.4%～19%之间。     

气相色谱-串联质谱技术分析烟草中的132种农药残留

利用气相色谱-串联质谱(GC-MS/MS)检测技术,建立了检测烟草中的132种农药残留的高灵敏度方法。分析过程中考察了不同萃取溶剂、不同缓冲盐体系、不同净化剂对目标物回收率的影响。最终确定烟草样品以乙腈进行提取,以N-丙基乙二胺(PSA)与碳18(C18E)的混合净化剂进行净化,氮气吹近干后用正己烷-丙酮(9:1, v/v)复溶,过有机滤膜后进行GC-MS/MS测定,内标法定量。132种农药在20～2000 μg/kg之间线性关系良好(r2 ＞0.99);所有农药的方法定量限(LOQ, S/N=10)均低于20 μg/kg;在50、200、500 μg/kg的加标水平下,除灭蚁灵及六氯苯回收率稍低外,其他农药的平均回收率为68.10%～123.15%,相对标准偏差(RSD)为1.79%～19.88%。对国际烟草科学研究合作中心(CORESTA)2012年共同实验的烟草样品进行检测,对比本方法与已有的标准方法,其结果一致性较好。该方法准确、可靠,灵敏度好,适用于烟草中132种农药残留的快速筛查与定性、定量分析。     

固相萃取-高效液相色谱-串联质谱法测定坚果中62种农药残留

建立了固相萃取-高效液相色谱-串联质谱(SPE-HPLC-MS/MS)法测定坚果中62种农药残留的分析方法。样品以乙腈提取,经正己烷脱脂后,采用TPH固相萃取小柱净化。待测物经Zorbax Eclipse Plus C18柱(100×3.0mm,1.8μm)分离,以乙腈-0.1%甲酸为流动相,梯度洗脱;采用电喷雾正离子源、多重反应监测模式检测;以保留时间和特征离子对(母离子和两个碎片离子)信息比较进行定性和定量分析。62种农药在各自线性范围内相关系数均大于0.993;在核桃、杏仁、花生仁三种基质中方法的定量限(以S/N≥10计)为0.1~10.0μg/kg,1、2、4倍定量限3个加标水平下,回收率为71.2%~112.7%,相对标准偏差为5.8%~14.1%。该方法灵敏度高、重复性好,检出限能够满足国内外对农药残留的最高限量要求,适合于坚果中农药残留的测定。     

气相色谱-质谱法分析烟草中有机磷农药残留量及其烟支转移率研究

建立了一种用加速溶剂萃取,自动固相萃取净化,气相色谱/质谱联用检测烟草中29种有机磷农药残留量的方法.考察了加速溶剂萃取仪的萃取温度、溶剂、加热时间和循环次数对回收率的影响,对固相萃取的洗脱溶液及其体积和流速进行了优化,利用保留时间和定性离子定性,以灭蚁灵为内标进行定量,29种有机磷农药的平均回收率在61.4%～128%之间,相对标准偏差在12%以下,符合烟草中农药多残留检测的要求.通过对烟支进行加标,探讨了有机磷农药向主流烟气和烟蒂的转移情况,其向主流烟气的平均转移率为小于6.3%,相对标准偏差为8.0%～18.5%,而烟蒂平均截留率为0.3%～15.0%,相对标准偏差为6.5%～21.3%,表明有机磷农药有较小的转移,为卷烟安全性评价提供了可靠的数据.     

HPLC-MS-MS法测定水体中残留的氨基甲酸酯类农药

应用高效液相色谱-串联质谱(HPLC-MS-MS)联用技术,建立了检测水体中氨基甲酸酯类农药残留的方法。水样经氨基柱固相萃取,二氯甲烷洗脱,梯度流动相洗脱,电喷雾正离子(ESI+)模式采集、选择反应性监测模式(SRM)对定性、定量离子进行MS/MS测定。5种氨基甲酸酯类农药在5～200ng/L范围内线性关系良好,回收率为80%～92%,相对标准偏差均小于10%,方法检出限分别为:异丙威和仲丁威为1.4ng/L,克百威和甲萘威为1.5ng/L,恶虫威为1.6ng/L。该方法适用于水体中氨基甲酸酯类农药残留的检测。     

液相色谱-四极杆-飞行时间质谱法快速筛查与确证紫甘蓝中415种农药残留

应用液相色谱-四极杆-飞行时间质谱(LC-QTOF/MS)建立了一次进样可同时对紫甘蓝中415种农药残留进行快速筛查和准确确证的分析方法。实验采用1%(v/v)醋酸乙腈溶液提取,无水硫酸镁和氯化钠进行盐析,ZORBAX SB-C18色谱柱(100 mm×2.1 mm, 3.5 μm)分离,以0.1%(v/v)甲酸水溶液(含5 mmol/L乙酸铵)-乙腈为二元流动相进行梯度洗脱,应用LC-QTOF/MS在电喷雾电离、全离子MS/MS(All Ions MS/MS)扫描正模式下进行检测,基质匹配外标法定量分析。通过优化全自动MS/MS采集模式(Auto MS/MS)和全离子MS/MS采集模式下的不同参数,得到每种采集模式下的最佳条件。然后在2种不同采集模式的最佳条件下对比,最终选取All Ions MS/MS采集模式。实验结果表明,采用所建立的分析方法可以准确定性和定量筛查紫甘蓝中415种农药残留,所有415种农药在各自的范围内线性相关系数(r²)均大于0.990,其中411种农药的筛查限(SDL)≤5 μg/kg, 413种农药的定量限(LOQ)≤10 μg/kg。在1倍、2倍和10倍LOQ添加水平下,农药的回收率分别为65.7%~118.4%、72.0%~118.8%和70.2%~111.2%,相对标准偏差分别为0.9%~19.7%、0.2%~19.9%和0.6%~19.9%。将该方法应用于2019年欧盟能力验证项目的紫甘蓝样品中未知农药残留筛查方法和定量方法考核样的检测,所有添加农药均被准确定性筛查和定量检测,没有假阳性和假阴性。结果表明,该方法快速、准确、可靠,适用于对紫甘蓝中多种农药残留的高通量定性筛查和准确定量,可以扩展到其他果蔬基质中多农残的高通量筛查。     

固相萃取-全二维气相色谱/飞行时间质谱同步快速检测蔬菜中64种农药残留

建立了蔬菜中64种农药残留同相萃取-全二维气相色谱-飞行时间质谱(GC×GC-TOF-MS)的测定方2.用乙腈提取样品,NH2-SPE周相萃取柱净化,甲醇-二氯甲烷溶液(5:95,V/V)洗脱,氮气吹扫浓缩,丙酮定容,全二维气相色谱(HP-5MS柱和DB17ht柱)-飞行时间质谱检测,基质曲线外标法定量.本方法的检出限...     

超高效液相色谱-四极杆-飞行时间质谱法快速筛查茶叶中的204种农药残留

利用超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF/MS)技术建立了茶叶中204种农药残留的快速筛查和确证检测方法。样品采用乙腈提取,经Carb-PSA固相萃取小柱净化,用乙腈-甲苯(3:1, v/v)洗脱,采用UPLC-Q-TOF/MS检测,外标法定量。建立了204种农药的一级精确质量数据库和二级谱图库,通过化合物的精确质量数、保留时间、同位素比值等信息对检测结果进行自动检索,从而在无对照标准品的情况下完成了204种农药的定性鉴定。结果表明,该方法可以同时对茶叶中204种农药残留进行快速筛查,在10、20、50 μg/kg 3个添加水平下的平均回收率为68.1%~117.2%,相对标准偏差为3.1%~18.9%。定量限均小于10 μg/kg。采用本方法对4份阳性样品进行检测,所得结果与GB/T 23205-2008的检测结果基本一致。该方法快速、灵敏、准确,可用于茶叶中204种农药残留的快速筛查。     

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。