高效液相色谱法测定动物组织中四环素类抗生素残留量的研究

建立了动物组织中四环素、金霉素、土霉素、强力霉素、去甲基金霉素、甲烯土霉素和二甲胺四环素等7种四环素类抗生素残留量的液相色谱同时测定方法。方法采用Inertsil C8-3(5μm,250 mm×4.0 mm i.d)反相色谱柱,以pH 4.0的EDTA-Mcllvaine缓冲溶液为提取溶液,以HLB固相萃取柱为净化柱,流动相为甲醇+乙腈+0.01mol/L三氟乙酸(梯度洗脱),流速1.5 mL/min,检测波长350 nm,进样量100μL。方法的检出限为1.5~5.0μg/kg,测定低限为50μg/kg,线性范围为50~1200μg/kg,加标回收率为73.8%~103%,相对标准偏差为0.5%~8.5%。方法适用于动物肌肉、肝脏和肾脏组织中7种四环素类抗生素残留量的同时检测。     

磁性固相萃取-高效液相色谱-串联质谱法测定环境水样中的四环素类抗生素

建立了磁性固相萃取-高效液相色谱-串联质谱同时测定环境水样中四环素类抗生素的方法。以6种四环素类抗生素(差向四环素、土霉素、四环素、去甲金霉素、金霉素和脱水四环素)为目标化合物,考察并优化了吸附和解吸条件,确定了最佳萃取条件。萃取后的目标化合物经ZORBAX Eclipse Plus C₁₈柱分离,用高效液相色谱-串联质谱在多反应监测(MRM)模式下进行检测。在优化的条件下,6种四环素在1~100 μg/L范围内线性关系良好,线性相关系数为0.9967~0.9993,检出限为2.44~25.21 ng/L,样品加标回收率为80.6%~90.0%,日内相对标准偏差(RSDs)为0.6%~2.5%,日间RSDs为1.1%~7.1%。该方法灵敏度高、背景干扰低,适用于环境水样中6种痕量四环素类抗生素的同时检测。     

分子印迹固相微萃取-高效液相色谱法测定水和牛奶中三种四环素类药物

以土霉素为模板分子制备了分子印迹固相微萃取涂层,建立了选择性萃取、高效液相色谱法同时测定牛奶和水样中四环素、盐酸土霉素和金霉素三种四环素类抗生素的分析方法。将0.1mmol盐酸土霉素在功能单体和交联剂的作用下制备分子印迹预聚合液,将经多巴胺处理后的不锈钢丝前端1~2cm置入其中,制备分子印迹固相微萃取涂层。3mL牛奶和水样经涂层萃取50min、解析5min,乙腈-10mmol/L磷酸盐缓冲液(PBS,pH=3)作为流动相,二极管阵列检测器(DAD)定量分析。实验结果表明,分子印迹涂层对四环素类目标物的特异性选择明显优于非印迹涂层。三种目标抗生素在100~1 000μg/L(牛奶)和10~1 000μg/L(水样)浓度范围内线性关系良好,相关系数在0.9959以上,四环素、盐酸土霉素和金霉素的检出限(S/N=3)为40~80μg/L(牛奶)和5~10μg/L(水样);加标水平为500μg/L时,回收率范围97.8%~109.0%,相对标准偏差(n=7)分别为5.3%~8.2%(牛奶),3.7%~6.4%(水样)。该方法前处理简单、绿色环保、选择性好、精密度好、回收率高,可用于牛奶和水样中上述三种四环素的实际检测。     

蜂蜜中残留抗生素的填充毛细管液相色谱法检测

采用新型毛细管高效液相色谱法和自行填充的毛细管色谱柱,以四环素、土霉素和金霉素为标准物,对蜂蜜中残留的四环素类抗生素进行了定量分析。方法具有操作简单、灵敏度高、定量准确的优点。在10μg/L至0.4mg/L的质量浓度范围内,土霉素、四环素和金霉素的线性相关系数分别为rOTC=0.99695,rTC=0.99778和rCTC=0.98836。毛细管高效液相色谱法可用于抗生素类物质的高灵敏度测定。     

高效液相色谱法测定水产品中四环素类抗生素残留

建立了一种高效液相色谱法测定水产品中土霉素、四环素、去甲基金霉素、金霉素、脱氧土霉素的分析方法。样品用5.0%高氯酸溶液提取,上清液用OasisHLB固相萃取柱净化,用紫外检测器于355nm测定。土霉素、四环素、去甲基金霉素检测限为0.01mg/kg,金霉素、脱氧土霉素检出限为0.02mg/kg。5种药物的回收率在74.8%~89.3%之间,相对标准偏差为3.95%~9.95%。方法适用于水产品中四环素类抗生素残留的检测。     

高效液相色谱-电喷雾串联质谱法测定畜禽粪便中四环素类抗生素

建立了高效液相色谱-电喷雾串联质谱法(HPLC-MS/MS)测定畜禽粪便中四环素类抗生素的分析方法。样品经甲醇-乙酸-水(体积比6∶3∶1)溶液提取,OASIS HLB小柱净化后,采用Waters Symmetry C18色谱柱(150×3.9mm,5μm)进行分离,以0.3%甲酸水溶液-0.3%甲酸乙腈溶液梯度洗脱,电喷雾正离子模式多反应监测(MRM)模式定量分析。在优化的色谱条件下,四环素、土霉素和金霉素在0.05~1.0mg/L范围内具有良好的线性,其检出限分别为0.025、0.084、0.098mg/kg;样品回收率为80%~103%。实验结果表明,该方法较液相色谱法具有更高的准确性和灵敏度,可满足畜禽粪便中四环素类抗生素残留的检测要求。     

限进材料固相萃取-高效液相色谱在线联用检测牛奶中四环素类抗生素残留

建立了一种限进材料固相萃取-高效液相色谱在线联用检测牛奶中四环素类抗生素残留的分析方法.利用原子转移自由基聚合法制备的限进型聚(苯乙烯-co-二乙烯苯)键合硅胶作为同时富集四环素类小分子和排阻蛋白大分子的固相萃取材料.经过限进萃取柱的净化和富集后,牛奶样品中的四环素类抗生素(土霉素、四环素和金霉素)被反冲进反相C18分析柱进行色谱分离和测定.牛血清蛋白在限进萃取柱上的洗脱率为96.0％,说明制备的限进材料具有很好的排阻大分子蛋白的效果.3种四环素类抗生素在牛奶样品中的加标回收率为88.3％～101.5％,RSD＜8.0％;方法检出限为50 ～ 80 μg/L,线性范围为0.05～ 2.0 μg/mL.结果表明,本方法简单高效,准确度好,检出限达到了规定要求,可以作为检测牛奶样品中四环素类抗生素残留的方法.     

高效液相色谱同时测定饲料中三种抗生素

建立了反相高效液相色谱法同时检测饲料中土霉素、四环素、金霉素的方法.色谱柱为AichromBond-AQ C18柱,150×4.6mm,粒度5μm;流动相:0.01mol/L磷酸二氢钠溶液(pH2.5)+乙氰,采用梯度洗脱,乙氰浓度在0～13min内由13%上升到40%;柱温35℃;流速为1.0mL/min;进样量101μL;检测波长375nm.方法检出限:土霉素和四环素0.25μg/mL、金霉素0.50μg/mL,回收率91.70%～101.19%,RSD<1.39%(n=7).     

LC-MS/MS法检测牛奶中14种β-内酰胺类抗生素残留

采用超高效液相色谱串联质谱建立了牛奶中14种β-内酰胺类抗生素残留检测方法。样品经过乙腈提取、氮吹、HLB柱净化后,经Acquity UPLC BEH Shield RP18(100 mm×2.1 mm,1.7μm)分离,以乙腈和体积分数0.02%甲酸溶液为流动相进行梯度洗脱,14种化合物在8 min内分离效果良好。方法的定量限均低于2.5μg/L,在2.5~250μg/L范围内线性良好,相关系数均在0.99以上;通过2,10,100μg/L 3个浓度的加标回收实验表明,回收率为73.2%~109.8%,RSD%为1.5%~12%,方法满足牛奶中β-内酰胺类抗生素药物残留检测要求。     

固相萃取-高效液相色谱法测定乳及乳制品中土霉素、四环素和金霉素残留

建立了固相萃取-高效液相色谱同时测定乳及乳制品中土霉素、四环素和金霉素的方法。样品经pH 4.0的Na2EDTA-mcllvaine缓冲溶液漩涡超声提取后,采用Oasis HLB固相萃取(SPE)小柱净化,洗脱液用N2吹至近干后用流动相溶解并定容,过PTFE滤膜后在Shiseido MG C18色谱柱上,以V(乙腈):V(10 mmol/L草酸)=27∶73的溶液为流动相进行分离,检测波长为360 nm。在最优的色谱条件下,各目标化合物的加标回收率为83.0%~109.2%,相对标准偏差在2.8%~6.1%之间。3种抗生素含量在0.10~20.0 mg/L范围内线性关系良好,相关系数≥0.999,乳及乳制品中土霉素、四环素和金霉素的检出限分别为10,10和20μg/kg。     

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。