青霉烷酸酯亚砜的2β-甲基选择性氯代--芳磺酰氯法

报道了芳磺酰氯对2α，2β-二甲基青霉烷酸酯的2β-甲基的高选择性氯代作用，讨论了它的应用和机理。     

反相高效液相色谱法快速测定长春花中4种生物碱

采用反相高效液相色谱法同时分离测定4种长春花吲哚类生物碱。以水：二乙胺=986：14，用磷酸调节pH=7．2(溶液A)，甲醇：乙腈=4：1(溶液B)，380mL A和620mL B混合作为流动相，流速2mL／min，进样量10μL，220nm下检测，以恒流洗脱方式在25min内分离了长春碱等4种成分。同时还研究了流动相组成、pH值等对分离效果的影响。对实际样品分析，取得了较好结果。     

Tautomeric equilibrium of ethyl acetoacetate in compressed CO2 + ethanol and CO2 + methanol mixtures

Tautomerism equilibrium of ethyl acetoacetate (EAA) in compressed CO2 + methanol and CO2 + ethanol mixtures was studied by UV-Vis spectroscopy at 308.15 K and different pressures. The volume expansion coefficient (alpha) of the solvents at different pressures was also determined. The relative permittivity (epsilon) of CO2 + methanol and CO2 + ethanol mixtures at different conditions was calculated using the Kc and Onsager solvent parameter. The equilibrium constant (Kc) of EAA in the binary mixtures increases considerably with increasing pressure or volume expansion coefficient. The relative permittivity or the polarity of the binary mixtures decreases sharply with increasing volume expansion coefficient in the range of 0 < alpha < 1.5. However, as the volume expansion coefficient exceeds 1.5, the relative permittivity decreases slowly. In other words, the dissolution of CO2 in the polar solvents can reduce the polarity of the solvents significantly in the low volume expansion coefficient range, and the polarity of the solution is not sensitive to the volume expansion coefficient as its value is large enough. The difference in polarity of the two solvents reduces with increasing pressure and becomes negligible after volume expansion coefficient exceeds about 2.5.     

卡尔曼滤波在极谱分析中的应用——Sn(Ⅳ)、Pb(Ⅱ)、In(Ⅲ)、Cd(Ⅱ)体系的同时测定

利用卡尔曼滤波（ＫＦ）技术，对互相干扰的Ｓｎ（Ⅳ）、Ｐｂ（Ⅱ）、Ｉｎ（Ⅲ）、Ｃｄ（Ⅱ）体系进行了定量测试研究。在５．００×１０５～３．００×１０４ｍｏｌ·Ｌ１的浓度范围内，各组分测试的相对误差为－４．０％～３．８５％。对大理石抛光粉管理样中的Ｓｎ（Ⅳ）、Ｐｂ（Ⅱ）进行了测定，结果与ＩＣＰＡＥＳ结果相符。回收率在９５．０％～１０４％之间。为保证ＫＦ的精度，使用了两个监控出口。数据说明效果良好     

The use of immobilized pH gradients for the detection of human polymorphisms in the forensic identification of bloodstains.

Some polymorphic proteins (alpha 1-antitrypsin, orosomucoid, transferrin, group specific component, plasminogen) and enzymes (phosphoglucomutase, acid phosphatase, estrase D) were determined in bloodstain extracts by isoelectric focusing with carrier ampholytes (CA) and with immobilized pH gradients (IPGs) rehydrated with CA. IPGs yield superior results for typing of genetics markers in bloodstains since phenotypes are better distinguished and the bands are straighter and sharper in the presence of contaminants. Also, the sensitivity of IPGs with CA is similar to isoelectric focusing (IEF) with CA. A new variant, ACP*B1, found in Negroid west African populations and not found in Caucasians is described. Such a variant can only be determined by IPGs since its isoelectric point (pI 5.95) is close to that of the ACP*B (pI 6.05) variant.     

Sigma-borane coordinated to nickel(0) and some related nickel(II) trihydride complexes

The reactions of the complexes [(dcype)NiH]2, 1, [(dippe)NiH]2, 2, and [(dtbpe)NiH]2, 3, with a mixture of BEt3 and Super-Hydride (LiHBEt3) afforded sigma-borane nickel(0) compounds of the type [(dcype)Ni(sigma-HBEt2)], 4, [(dippe)Ni(sigma-HBEt2)], 5, [(dtbpe)Ni(sigma-HBEt2)], 6, respectively, with the concomitant formation in each case of [(dcype)2Ni2)(H)3][BEt4], 7, [(dippe)2Ni2(H)3][BEt4], 8 and [(dtbpe)2Ni2(H)3][BEt4], 9, respectively. X-ray crystal structures are reported for 4 and 8.The reaction of BEt3 and LiHBEt3 was also reviewed in detail.     

Simultaneous determination of pentachlorophenol and carbaryl in water

Summary A rapid method for the simultaneous determination of pentachlorophenol (PCP) and Carbaryl in water is described. A 1 liter water sample is extracted with hexane after acidification with concentrated H₂SO₄. After evaporation to a small volume, the extract is analyzed by gas chromatography-mass spectrometry, operating in the selected ion monitoring mode. Estimated detection limits are 0.08 g L^–1 for PCP and 0.11 g L^–1 for Carbaryl, with recoveries of 96% for PCP and 97% for Carbaryl.     

新型引发体系——Cu(Ⅲ)络离子引发聚合反应动力学的研究(Ⅰ)——丙烯酰胺自还原引发聚合反应

二过碘酸合铜(Ⅲ)络离子在小分子氧化反应动力学方面的研究已有报道。但用于自由基聚合反应方面的研究至今尚未见报道。本文系用膨胀计法研究了Cu(Ⅲ)为氧化剂、丙烯酰胺(简称AM)为还原剂引发AM聚合反应动力学,得到聚合速率方程及聚合物分子量,探讨了反应机理。 1 实验部分 1.1 仪器和试剂 超级恒温水浴(精度±0.1℃);测高仪;UV-3000分光光度计(日本津鸟);红外光谱仪(日立260-50),试剂除AM外,其它均为分析纯。     

修饰离子聚合度对膜-颗粒体系静电自组装的影响

采用不同聚合度的季铵阳离子聚合物作为修饰离子,对纳米Pt颗粒的合成及其在全氟磺酸膜(Ｎａｆｉｏｎ)上的静电自组装行为进行了研究,结合Ｎａｆｉｏｎ膜电导率的变化对膜-颗粒自组装机理进行了分析。结果表明:自组装过程中Ｎａｆｉｏｎ膜电导率的下降总是比Pt组装量的上升先达到平衡,表明膜-颗粒体系(MPS)的静电自组装是一个先由大量的小阳离子占据空位,然后由离子修饰的大颗粒(纳米Pt)取代的过程；改变修饰离子的聚合度同时会引起组装液中游离修饰离子的数目的变化,从而对电导率的衰减速度和组装第二阶段的脱附-组装平衡造成影响,因此随着修饰离子聚合度的增加,导电率达到平衡的时间增加,组装量达到平衡的时间减少。     

Resolution of ternary mixtures of salicylic, salicyluric and gentisic acids by partial least squares and principal component regression: Optimization of the scanning path in the excitation-emission matrices

The resolution of ternary mixtures of salicylic, salicyluric and gentisic acids has been accomplished by partial least squares (PLS) and principal component regression (PCR) multivariate calibration. The total luminescence information of the compounds has been used to optimize the spectral data set to perform the calibration. A comparison between the predictive ability of the three multivariate calibration methods, PLS-1, PLS-2 and PCR, on three spectral data sets, excitation, emission and synchronous spectra, has been performed. The excitation spectrum has been the best scanning path for salicylic and salicyluric acid determinations, while the emission spectrum has been the best for the gentisic acid determination. The convenience of analysing the total luminescence spectrum information when using multivariate calibration methods on fluorescence data is demonstrated.