柱后衍生高效液相色谱法测定罗汉果甜甙中黄曲霉毒素B1

用柱后衍生高效液相色谱法测定了罗汉果甜甙中黄曲霉毒素B1（AFX B1）。用MYCOTOX^TM C18作为反相色谱柱,流动相为由甲醇、乙腈及水以22＋22＋56之比例混合的混合液。柱后衍生试剂为100mg·L^-1碘的水溶液,以荧光检测器在发射波长为365nm及激发波长为430nm条件下进行测定。在AFX B1的峰面积与质量浓度（mg·L^-1）之间呈线性关系,其回归方程为y=14．222x＋0．6253（r=0．998）,在三个浓度水平（5．1,40．8及102μg·kg^-1）上进行回收率及精密度试验,所得回收率在81．4％～94．2％之间,相对标准偏差（n=10）在2．1％～4．59／5之间。     

应用液-液色谱联用技术在线富集测定环境水中西维因和抗蚜威的残留量

为高效液相色谱法测定环境水样中残留的西维因和抗蚜威的含量,应用了液-液色谱联用技术,实现了在线富集、分离和检测。分析中用YWG-C18（10mm×4．6mm,10μm）和YWG-C18（150mm×4．6mm,10μm）依次作为富集柱和分离柱,以体积比45比55混合的甲醇与水的混合溶液作为流动相,其流速为1．0mL·min^-1。选定紫外光度检测的波长为228nm,试样溶液在富集柱上的流速为5．0mL·min^-1。此外,对渗漏体积等参素也作了试验,分析信号值与两农药的质量浓度在0．04～1．0μg·L^-1范围内呈线性关系。测得方法的检出限（S／N=3）为0．008μg·L^-1（西维因）和0．014μg·L^-1（抗蚜威）,回收试验的结果在93％～119％之间。还对日内和日间精密度进行了试验,测定西维因的日内精密度为1．3％～20．0％,日间精密度为2．39／6～22．2％,测定抗蚜威的日内精密度为2．0％～10．8％,日间精密度为2．2％～5．8％。     

反相高效液相色谱法测定α-（2-氨基噻唑-4-基）-α[（叔-丁氧基羰基）异丙氧亚胺基]-乙酸

提出了制备头孢类抗生素的中间体α-（2-氨基噻唑-4-基）-α-[（叔-丁氧基羰基）异丙氧亚胺基]-乙酸（ATIA）的反相高效液相色谱测定方法,采用Spherigel^TM C18色谱柱（250mm×4．6mm,5μm）,以0．05g·L^-1四丁基溴化铵的甲醇-水（6＋4）溶液为流动相,流速为1mL·min^-1,柱温30℃,检测波长260nm,以外标法定量。在0．001～1．0mg范围内,ATIA的质量与峰面积呈线性关系,回归方程为A=31475．6m＋1786.7,相关系数为0．9997,以质量为0.06mg ATIA按方法测定6次,算得其相对标准偏差为3．7％,检出限（3S）为0．6μg,回收率的试验结果在98．8％～104．0％之间。     

高效液相色谱-荧光光度检测尿液中溴鼠灵

提出了高效液相色等荧光光度检测尿液中溴鼠录。尿液经磷酸酸化至pH2．0并在LC-18固相萃取小柱上富集、净化,分取10．0μL试样溶液进行高效液相色谱测定。用XDB C18柱（150mm×2．1mm,5μm）为固定相,以甲醇及稀乙酸溶液（2＋998）以88比12的比例混合后作为流动相,在激发波长为270nm,发射波长为376nm的条件下进行荧光光度检测。结果表明：溴鼠灵在0．05～10．0mg·L^-1范围内呈线性关系,方法的回收率在79．8％～97．0％之间,相对标准偏差在4．0％～4．9％之间,测定限为0．07mg·L^-1。     

微柱富集-石墨炉原子吸收光谱法测定痕量钼

提出和制备了一种负载苯基荧光酮（PF）的滤纸纤维柱,用于石墨炉原子吸收光谱法测定痕量钼的预富集。试验表明：在pH2．0时,控制待测液流速在2．0mL·min^-1以内,可定量富集钼（Ⅵ）,饱和吸附量为25．2μg·g^-1。用流速1．0mL·min^-1的氨水（3＋97）2．0mL,可将5．0μg钼（Ⅵ）从吸附柱上定量洗脱。对国家地质标准物质GSS5和GSR1的分析结果表明,该方法可靠。测定了人工合成锌样、铜精矿中痕量钼,方法的检出限为1．01μg·L^-1,回收率为92．0％～103．0％。     

大口径石英毛细管柱气相色谱法测定黄豆甙原中有机溶剂残留量

用毛细管气相色谱法测定黄豆甙原中有机溶剂残留量。试样0．5g溶于含有内标正丁醇的二甲亚砜中,定容5mL。在优化条件下,用配有DB-17石英毛细管分离柱（0．54mm×30m,1．0μm）和火焰电离检测器的毛细管柱气相色谱仪测定黄豆甙原中残留的有机溶剂乙醇和N,N-二甲基甲酰胺（DMF）。乙醇和DMF的检出限分别是9．6pg和5．7ng;回归方程和相关系数分别为Y=0．04627＋0．65369X,r=0．9982和Y=0．02531＋0．35654X,r=0．9934;线性范围分别为50．4～718.9g·L^-1和9．8～137．2g·L^-1。     

高效液相色谱法测定动物源食品中磺胺类药物残留量

试样中残留磺胺药物用乙腈提取并经正己烷萃取和通过碱性氧化铝层析柱进行净化。所得乙腈-水（30＋70）洗脱液用于高效液相色谱法测定。采用C18色谱柱（250mm×4．6mm）作固定相,以乙腈（A）及乙腈＋乙酸＋水（20＋1＋79）的混合液（B）按不同比例混合液作流动相进行梯度淋洗使5种磺胺药物分离,最后在270nm波长处作紫外检测,所测定的磺胺药物的质量浓度与其峰面积之间在0．05～1.00mg·L^-1范围内呈线性关系。方法的测定下限（S／N=10）为0．04mg·kg^-1,以猪肉样品为基体加入3种药物的标准溶液进行回收试验,测得回收率在73．65％～93．45％之间。     

微波消解样品-冷原子吸收光谱法测定鱼粉中微量汞

以微波溶样技术消解样品,采用正交试验设计优化冷原子吸收光谱法测定汞的试验条件,并对微波消解条件和共存离子的干扰进行了试验。试验表明：汞含量在30μg·L^-1范围内服从比耳定律,方法的检出限为0．13μg·L^-1,相对标准偏差为2．6％,回收率为97．6％～106．8％。     

卤代荧光素与西布曲明相互作用的共振散射光谱特征及其分析应用

利用共振瑞利散射法,研究了乙基曙红、赤鲜红和荧光桃红3种卤代荧光素与盐酸西布曲明的相互作用,发现这3种卤代荧光素与盐酸西布曲明形成了离子缔合物,产生强烈的共振瑞利散射信号,其最大散射峰分别位于316、573和370nm;考察了适宜的反应条件及共存物质的影响,在一定范围内盐酸西布曲明的浓度与共振瑞利散射强度成正比,其线性范围分别是0．1～4．2mg·L^-1（乙基曙红-盐酸西布曲明体系）、0．09-6．0mg·L^-1（赤鲜红-盐酸西布曲明体系）、0．06～3．0mg·L^-1（荧光桃红-盐酸西布曲明体系）,其检出限分别为32、28和21μg·L^-1;在赤鲜红-盐酸西布曲明体系中,573nm处的共振散射光谱偏振度P为0．95,表明体系的共振散射光谱主要由散射光构成。     

十六烷基三甲基溴化铵-溴化钾-硝酸钠体系浮选分离铂(Ⅳ)

在pH3．0的克拉克-鲁布斯缓冲溶液中,铂（Ⅳ）以PtBr5^2-·2CTMAB＋的形式从含有0．59mol·L^-1硝酸钠、5．0×10^-3mol·L^-1溴化钾及3．0×10^-1mol·L^-1十六烷基三甲基溴化铵（CTMAB）的试液中定量浮选分离。此方法中浮选分离时试液的总体积定为10mL,其中合0．1mol·L^-1溴化钾溶液0．5mL,0．01mol·L^-1CTMAB溶液3mL及硝酸钠0．5g。试验结果表明：100／lg铂（Ⅳ）有效地与多达1．0mg的铬（Ⅲ）、锰（Ⅱ）、铝（Ⅲ）、镍（Ⅱ）、镓（Ⅲ）、铁（Ⅱ）及锌（Ⅱ）分离,铂（Ⅳ）的浮选率迭100％。此方法应用于已知含铂0．102％（质量分数）的Ni—Pt／Al2O3催化剂的分析,测得铂量的平均值为0．099％,测定值的相对标准偏差（n=7）为2．2％。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

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。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

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.