气相色谱法检测七种动物源食品中莠灭净残留量

本研究建立了动物源食品中莠灭净残留量的气相色谱检测法。样品以乙腈为提取溶剂,提取液以酸性氧化铝柱净化,乙腈-甲苯(7∶2,V/V)洗脱,以气相色谱火焰光度检测器(GC-FPD,S型滤光片)检测,外标法定量。方法的准确度与精密度较好,检出限为0.005mg/kg,平均添加回收率在88.1%～102.8%之间,相对标准偏差(RSD)为3.07%～8.29%,满足农药残留分析的要求。     

基于气-液微萃取结合气相色谱-质谱法快速检测植物源性食品中28种农药残留

利用气-液微萃取(Gas-Liquid Microextraction,GLME)技术,结合气相色谱-质谱法建立快速检测植物源性食品中农药残留的分析方法.准确称取3 g匀浆样品,加入3 mL二氯甲烷∶乙酸乙酯(1∶1,V/V)超声提取15 min,取上清液100 μL,通过GLME技术进行萃取净化,结合内标法,联用气相...     

气相色谱和气相色谱-质谱法测定食品中乙草胺残留

建立了气相色谱和气相色谱-质谱法检测10种植物源性和动物源性食品中乙草胺残留量检测方法.粮谷类和动物源性样品采用乙腈提取,GPC结合硅胶固相萃取柱净化;蔬菜类样品采用乙酸乙酯提取、硅胶固相萃取柱净化;元葱等样品先进行微波消解,然后采用乙酸乙酯提取,硅胶固相萃取柱净化.气相色谱和气相色谱-质谱联用法检测.两种方法检出限均为0.004 mg/kg; 在0.01～0.16 mg/L范围内均呈良好的线性关系,相关系数为0.9998和0.9997;在0.01、0.02和0.05 mg/kg的添加水平下,添加回收率在70%～102%之间;相对标准偏差(RSD)均小于10%.     

食品中聚二甲基硅氧烷检测方法研究

建立了裂解气相色谱-质谱(PGC-MS)测定食品中聚二甲基硅氧烷残留量的方法。样品中的聚二甲基硅氧烷以石油醚-乙酸乙酯(5∶1,体积比)提取,通过硅胶小柱净化,经石油醚淋洗除去油脂后,用石油醚-乙酸乙酯(5∶1)洗脱。采用裂解气相色谱-质谱法将聚二甲基硅氧烷热裂解为小分子产物,测定裂解产物的组成,以相对分子质量相差74的系列甲基环硅氧烷作定性成分,以六甲基环三硅氧烷基为定量指标,以m/z207作定量离子,选择离子监测法(SIM)定量。方法的线性范围为10~500 mg/L,相关系数为0.995,加标回收率为91%~103%,相对标准偏差为7.1%~8.3%,定量下限(S/N=10)为5 mg/kg。方法适用于食品中微量聚二甲基硅氧烷的检测。     

气相色谱-质谱法测定动物源性食品中残留的葚孢菌素

建立了气相色谱-质谱法检测动物源性食品中葚孢菌素残留量的方法.采用环己烷-二氯甲烷(体积比为9:1)振荡提取,中性氧化铝固相萃取柱净化,气相色谱-质谱法进行测定,选择离子监测模式检测.通过方法优化,确定方法检出限为0.01 mg/kg(S/N=10),在0.005～1 mg/kg范围内线性关系良好(R2=0.9999)...     

加速溶剂萃取-凝胶色谱净化高效液相色谱法测定动物源性食品中的胆固醇

采用加速溶剂萃取-凝胶色谱净化建立了动物源性食品中胆固醇检测的高效液相色谱方法。结果表明,胆固醇浓度在1.0~40.0mg/L范围内线性关系良好,加标回收率为89.1%~99.8%,相对标准偏差为3.1%~7.8%。该方法准确、灵敏度高,适用于富含脂类的动物源性食品中胆固醇的检测。     

高效液相色谱-串联质谱法测定动物源食品中粘杆菌素、多粘菌素B的残留量

建立了动物源食品中粘杆菌素和多粘菌素B残留的高效液相色谱-串联质谱(HPLC-MS/MS)测定方法。样品用V(10%三氯乙酸水溶液):V(乙腈)=30:70提取,Oasis WCX SPE柱净化,LC-MS/MS电喷雾正离子多反应监测模式(ESI+-MRM)检测。分析物在0～250μg/kg的浓度范围内呈良好线性,线性相关系数>0.995。方法的定量限为10μg/kg。方法在三个添加水平的平均回收率在71.6%～78.9%之间,相对标准偏差在6.2%～12%之间。方法适用于动物源食品中粘杆菌素和多粘菌素B的定量及确证检测。     

气相色谱－三重四极杆质谱法测定动物源性食品中砜吡草唑残留量

建立了动物源性食品中砜吡草唑残留量的气相色谱－三重四极杆质谱检测方法。猪肉、猪肝、鸡肉、鸡肝、牛奶和鸡蛋中的砜吡草唑用乙腈提取,经乙二胺-N-丙基硅烷化硅胶、十八烷基键合硅胶和无水硫酸镁去除杂质,离心后取上清液氮吹至干,加入丙酮复溶、过滤后经气相色谱－三重四极杆质谱检测,外标法定量。通过对仪器条件、提取溶剂和净化方式等进行优化,确定最合适的前处理方法和仪器条件。对样品的基质效应进行考察,发现6种基质中砜吡草唑的基质效应均小于20%,为弱基质效应,无需采取补偿措施。在优化实验条件下,砜吡草唑在0.5 ~ 100 μg/L范围内线性关系良好,相关系数为0.999 5。空白样品在4个加标水平下的平均回收率为85.8% ~ 106%,相对标准偏差（n = 6）为3.1% ~ 6.8%,方法定量下限为0.001 mg/kg。采用该方法对50个动物源性食品进行测定,在1个牛肉样品和1个羊肉样品中检出砜吡草唑。该方法操作简单、灵敏度高、准确性好,适用于动物源性食品中砜吡草唑的检测,可为砜吡草唑在动物源性食品中的风险监控提供技术支撑。     

动物源食品中呋喃苯烯酸钠残留的液相色谱串联质谱法检测

建立了液相色谱串联质谱法测定动物源食品(猪肝、猪肾、猪肉、鳗鱼、蜂蜜、鸡蛋)中呋喃苯烯酸钠残留的检测方法.样品采用乙腈提取,正己烷萃取净化,并对液相色谱串联质谱分离条件以及样品前处理条件进行了优化.呋喃苯烯酸钠的线性范围为2.0 ～50.0 μg/L,线性良好,相关系数均大于0.999 0,回收率为82% ～90%,日内相对标准偏差为0.9% ～5.8%,方法的定量下限为5.0 μg/kg.方法可满足进出口动物源食品中呋喃苯烯酸钠残留的确证与测定.     

衍生化毛细管气相色谱法同时测定无糖食品中的多种糖醇类甜味剂

建立了一种同时测定无糖食品中多种糖醇类甜味剂的气相色谱定量分析方法。样品中的糖醇经水提取,净化、脱水后,在吡啶-乙酸酐(1∶1,V/V)存在条件下,于90℃反应20 min,生成的糖醇乙酸酯衍生物用OV-101毛细管色谱柱(50 m×0.25 mm×0.33μm)分离,氢火焰离子化检测器(FID)进行测定及气相色谱-质谱结构鉴定。在优化的色谱分析条件下,实现了赤藓糖醇、木糖醇、甘露糖醇、山梨糖醇和麦芽糖醇衍生物的理想分离,并排除了常见糖类对糖醇测定的干扰。本方法在0.01～1.6 mg/mL范围内,对糖醇浓度与其衍生物峰面积进行线性回归分析,其相关系数在0.9995～0.9999之间。平均回收率为74.6%～113.4%,相对标准偏差在2.4%～8.6%之间。本方法操作简便、快速、可靠,检测限和加标回收率均能满足无糖食品中糖醇的定量分析要求。     

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.     

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。