烟草中氨基甲酸酯农药残留量在卷烟烟气中捕集转移率的测定

用Florsil小柱固相萃取分离纯化、气相色谱定性定量同时测定卷烟中5种氨基甲酸酯类农药（西维因、叶蝉散、速灭威、呋喃丹、灭多威）在卷烟烟气中的捕集转移率（CSE）。用OV－101毛细管色谱柱为分离柱,FID（火焰离子检测器）检测。5种农药在12min内得到很好分离。线性范围1－25mg/L,检出限11－16ng。CSE分别为4．3％－10％。     

流动注射在线预富集-高效液相色谱法测定四种硝基类化合物

建立了以香烟过滤嘴纤维作吸附剂,在线固相萃取-高效液相色谱（SPE—HPLC）测定水中邻硝基苯甲酸、对硝基苯胺、邻硝基苯酚、3-氯硝基苯四种硝基类化合物的方法。邻硝基苯甲酸、对硝基苯胺、邻硝基苯酚、3-氯硝基苯分别在0．006～4．80、0．003～2．40、0．002～1．60、0．002～1．60mg／L范围内峰面积与浓度呈线性关系,相关系数分别为0．9994、0．9996、0．9997和0．9996;检出限（S／N=3）分别为1．0、0．8、0．6,0．6μg／L;富集倍数分别为28．2、176．6、172．1、153．3。该法用于河水中四种硝基类化合物的测定,回收率为85．41％～116．44％,相对标准偏差在1．1％～5．4％范围内。     

胶束毛细管电泳在线推扫富集技术测定工业废水中痕量苯酚和硝基苯酚

利用胶束毛细管电泳在线推扫富集技术建立了测定工业废水中痕量苯酚、邻硝基苯酚和间硝基苯酚的方法。采用未涂层熔硅弹性石英毛细管(60cm×75μm,有效柱长52cm),选择20mmoL/L硼-砂80mmoL/L十二烷基硫酸钠(SDS)(pH9.45)为缓冲溶液,分离电压18kV,紫外检测波长214nm,在200s内可实现苯酚、邻硝基苯酚、间硝基苯酚的分离检测。在优化条件下,苯酚、邻硝基苯酚、间硝基苯酚的检出限分别为0.03、0.020、.02mg/L;相对标准偏差RSD(n=3)分别为3.42%、4.15%、3.48%;间硝基苯酚富集倍数可达1000倍。     

反相高效液相色谱法分离和测定硝基苯酚的三种异构体

采用反相高效液相色谱法分离和测定了硝基苯酚的三种异构体，其邻、间、对三种硝基苯酚的检出限分别为4．6、6．9和9．3μg／L，相对标准偏差为6．4％、7．1％和4．9％．     

毛细管气相色谱法分离分析苯酚和水杨醛

采用毛细管气相色谱法对由苯酚和甲醛为原料合成的水杨醛及反应物苯酚进行了分离分析。研究了水杨醛与苯酚分离的最佳条件，用正十四烷作内标物进行定量，水杨醛、苯酚在0．5～6．0g／L内有良好的线性，加标平均回收率分别为97、3％、99、0％，测定结果的相对标准偏差小于5％。     

高效毛细管电泳电导法快速检测复方维生素B片中的VBl、VBl2、VB6和VC

采用高效毛细管电泳电导法同时分离、测定了复方维生素B片中的主要成分VB1，VB12，VB6和VC的含量。研究了运行缓冲溶液的酸度和浓度、电泳电压、进样时间等因素对电泳的影响。在优化的实验条件下：40mmol/L Tris-4mmol/L H3BO3(pH8．0)的缓冲溶液中加入0．30mmol/L CTAB(溴化十六烷基三甲基铵)，分离电压为15kV，上述4组分在5min内得到良好的分离。维生素B1，B12，B6和VC的线性范围分别为5．5～1．0mg/mL；15～1．5mg／mL;1．0～0．40mg／mL和6．6～0．80mg／mL；检测限分别为0．80μg/mL，4．0μg/mL，0．50μg/mL，2．9μg/mL；5次测定峰高的相对标准偏差分别为2．2％，1．6％，3．9％，2．8％。5次测定的平均回收率分别为99％，94％，l00％，97％。     

糊精介质中西酞普兰的毛细管电泳手性分离与定量测定

以糊精作为毛细管电泳手性分离选择剂,对药物西酞普兰对映体的分离进行研究。考察了糊精浓度、缓冲液体系离子强度和pH及分离电压对对映体分离的影响。在糊精7．0％（m／V）、磷酸盐80mmol／L（pH5．4）的运行缓冲液中,分离电压20kV时,西酞普兰对映体分离度达3．9,同时对拆分机理进行了初步探讨。测定S-（＋）-西酞普兰原料药中R-（-）异构体的含量,在0．05～4．00g／L浓度范围内线性关系良好,R-（-）．西酞普兰与S-（＋）-西酞普兰的检出限分别为25．3mg／L和27．3mg／L,线性相关系数均在0．9970以上;RSD低于3．2％。     

β-环糊精增敏荧光法快速测定蔬菜中有机磷农药残留

植物酯酶催化底物乙酸-1-萘酯分解为荧光物质1-萘酚,采用荧光法测定1-萘酚的荧光强度,由于β-环糊精对1-萘酚的包络作用,荧光强度显著增加,使检测灵敏度得以提高．该体系用于蔬菜中甲胺磷农药残留测定,相关系数R为0．997,线性范围为2～50mg／L,方法的检测限为0．5mg／L．     

毛细管电泳法分析西维因等农药

 采用毛细管电泳法对西维因和 4种三嗪类农药进行了分离研究 ,考察了溶液的 pH值、胶束浓度和有机改性剂对分离的影响。以 2 0mmol/L硼砂 5 0mmol/L十二烷基硫酸钠 10 % (体积分数 )甲醇溶液 (pH 9 2 )为电泳缓冲液 ,采用压力进样方式 ,在 2 5kV恒压下进行分离 ,并在波长 2 2 5nm处检测 ,各组分可达到基线分离。在质量浓度为 30mg/L～ 2 0 0mg/L时 ,西维因标样的线性关系良好。该方法应用于西维因原药实际样品的测定 ,结果令人满意 ,西维因的加标回收率为 93 4 %～10 1 3% ,其峰面积的RSD为 2 5 9%。     

毛细管电泳法分离测定芦丁、槲皮素和连翘苷

用毛细管电泳紫外检测法同时测定了芦丁、槲皮素和连翘苷，研究了各种条件的影响，得到了优化的实验条件，在20mmol/L的Na2B4O7(H3B03调节至pH8．40)-30mmol/L十二烷基硫酸钠-10％乙腈(1 9)的缓冲溶液中，分离电压为12kV时，芦丁、槲皮素和连翘苷在10min内得到了良好的分离，检测波长为254nm，芦丁、槲皮素和连翘苷分别在0．01-1．0mg/mL，0．01-1．0mg／mL和0．05-1．0mg/mL质量浓度范围内与电泳峰高呈现良好线性关系，检测下限分别为0．005mg/mL，0．005mg/mL和0．01mg／mL，应用于实际样品的测定。     

Optimization of parameters for semiempirical methods. III Extension of PM3 to Be,Mg, Zn,Ga, Ge,As, Se,Cd, In,Sn, Sb,Te, Hg,Tl, Pb,and Bi

Using a recently developed procedure for optimizing parameters for semiempirical methods,¹ PM3 has been extended to a total of 28 elements. Average ΔH_f errors for the newly parameterized elements are Be: 8.6, Mg: 8.4, Zn: 5.8, Ga: 14.9, Ge: 11.4, As: 8.5, Se: 11.1, Cd: 2.6, In: 11.3, Sn: 9.0, Sb: 13.7, Te: 11.3, Hg: 6.8, Tl: 6.5, Pb: 7.4, and Bi: 10.9 kcal/mol. For some elements the paucity of data has resulted in a method, which, while highly accurate, is likely to be only poorly predictive.     

Prediction of the enthalpy of vapourisation for anhydrides,formates, acetates,propionates, butyrates,esters, and ethers

Four analytical correlations based on the use of the corresponding states principle were used to calculate the enthalpy of vapourisation of fluids. Three of these correlations require as inputs the critical temperature and the acentric factor. The fourth requires a molecular Lennard–Jones parameter and the acentric factor. Results for 184 polar and non-polar fluids grouped into 9 families are compared with the values accepted by the Design Institute for Physical Property (DIPPR) project. Recommendations are given for the use of each model and for the choice of the adequate model for each family of fluids.     

ICP-AES法测定铝中铁、硅、铜、镓、镁、锌、锰和钛

用 50g L氢氧化钠溶液溶解铝样品 ,硝酸 (1 1 )酸化 ,以ICP AES测定其中铁、硅、铜、镓、镁、锌、锰和钛等 8种杂质元素。     

ICP-MS测定化妆品中铍、镉、铊、铬、砷、碲、钕、铅

目的：建立化妆品中铍、镉、铊、铬、砷、碲、钕、铅8种有害元素的测定方法。方法：采用电感耦合等离子体质谱法,样品采用微波消解,以钇、锂、铟、铋为内标作定量分析。结果：各元素和内标元素在一定浓度范围内的质量数比值均与浓度呈良好的线性关系,线性方程的相关系数均大于0.9998,平均回收率为95%~104%,相对标准偏差(RSD)均小于3%。结论：该方法灵敏度高,准确,可为化妆品中上述元素的限量检查提供参考。     

猪胰脏中铁钙镁铜铅锌镉锰钴镍的测定

采用硝酸－过氧化氢在自动回流消化仪中消化猪胰脏,火焰原子吸收光度法测定铁、钙、镁、铜、锌、铅、镉、锰、钴、镍的含量。,方法简便,快速,结果令人满意,并对猪胰脏食用价值进行了评价。     

Thin-layer chromatographic separation of aldrin,dieldrin, γ-hexachlorocyclohexane,malathion, ethyl-parathion,pentachlorophenol, and of chlordane,dieldrin, γ-hexachlorocyclohexane,malathion, ethyl-parathion,and pentachlorophenol from each other

A thin-layer chromatographic method is reported for the separation of aldrin (or chlordane), dieldrin, γ-hexachlorocyclohexane, malathion, ethyl-parathion, and pentachlorophenol from each other. The procedure, however, does not separate aldrin and chlordane from each other although it does separate either pesticide from the other components. The method employs alumina plates with n-hexane:xylene:benzene:toluene:cyclohexane:methyl cyclohexane (50:50:50:50:50:50:) as developing solvent.     

Enthalpies of dilution of aqueous solutions of formamide,acetamide, propionamide,andN,N-dimethylformamide

The enthalpies of dilution of aqueous solutions of formamide, acetamide, propionamide,N,N-dimethylformamide, and sucrose have been measured from about 0.15 to 2.0 moles-kg ^–1 at 25.0°C. The results of the enthalpy measurements were used to calculate the pairwise enthalpies of interaction for each compound with itself. The equation of Savage and Wood together with their interaction parameters are used to predict the experimental results. All of the predictions are within the standard deviation of the original correlation of Savage and Wood (±220 J-kg-mole ^–2 ). Detailed examination of the results shows that specific effects are present but they are less than 220 J-kg-mole ^–2 . Results on urea and substituted ureas are used to determine interaction coefficients for a urea group with itself and with another CH ₂ group. The result,H _U,U =–280 andH _{U,CH 2} =29 J-kg-mole ^–2 , is an improvement on the previous arbitrary assignment of parameters for urea interactions.     

Theoretical Study of Molecular Structure,Reactivity, Lipophilicity,and Solubility of N-Hydroxyurea,N-Hydroxythiourea,and N-Hydroxysilaurea

Ab initio molecular orbital methods at the CBS-QB3 level of theory have been used to study the structure and gas-phase stability of various tautomers and rotamers of N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, their anions and protonated forms. The geometries of N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, their anions and cations were optimized at the Becke3LYP/CBSB7 level of theory. For all compounds studied, the amidic form is computed to be substantially more stable than the iminolic tautomer. N-Hydroxyurea and its thio and sila derivatives are computed to behave as Nacids in the gas phase. These compounds are in gas-phase weak acids with a calculated acidity of about 1425 to 1355 kJ-mol^–1. Basicities increase in the order: N-hydroxyurea < N-hydroxythiourea < N-hydroxysilaurea. The most stable protonated structures are represented by several isomers with almost equal stability. Thus, in the N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, both protonation at the double bonded (C=O, C=S and Si=O) oxygen and sulfur atoms, as well as the protonation at the N(H)OH nitrogen basic center is equally probable. The experimental pK _a value (10.6) of N-hydroxyurea and the computed value (9.7) for its monohydrated complex with the specifically hydrogen-bonded water molecule to the ionizable OH group are in a good agreement. The experimental partition coefficient of N-hydroxyurea is best reproduced by the Alog P_s method. The formation of nitroxide radical in the reaction of N-hydroxyurea and its sulfur and silicon substituted derivatives with the phenol radical is an exothermic process. Thus, the \bondN(H)OH moiety of these compounds may quench the structurally related tyrosyl radicals in the active site of ribonucleotide reductase.