以硫醚为主链的螯合树脂研究Ⅰ.4-氨基安替吡啉树脂和乙基原磺酸基树脂的合成及吸附性能

聚环硫氯丙烷或环硫氯丙烷与环氧氯丙烷共聚物，在少量二乙烯三胺存在下制得交联预聚物，将交联预聚物与4－氨基安替吡啉（4AAP）或乙基原磺酸钾（PEA）反应，制得四种侧链带氨基安替吡啉，乙基原碘酸基的新型螯合树脂。它们对贵金属具有优良的吸附性能和高的吸附选择性。并通过X－射线光电子能谱初步探讨了树脂对金属离子的螯合作用。     

Sensitive HPLC-fluorometric and HPLC-MS determination of diarrhetic shellfish poisoning (SP)-toxins as 4-bromomethyl-7-methoxycoumarin esters

 Extracts containing the diarrhetic shellfish poisoning (DSP) toxins okadaic acid (OA), dinophysistoxin-2 (DTX₂), and dinophysistoxin-1 (DTX₁) were purified on a silica gel cartridge and derivatized with 4-bromomethyl-7 methoxycoumarin (BrMmc). After pre-column derivatization the BrMmc derivatives of the DSP toxins were directly injected into an HPLC system, isocratically eluted, and quantified by fluorescence detection. The signals of the esters showed good linearity in the fluorescence detector within the examined contamination range of 0.03 mg DSP/kg to 2.5 mg DSP/kg. The detection limits for the DSP toxins as 7-Mmc esters were 0.04 ng (corresponding to 0.05 mg DSP/kg). The chromatographic conditions allow to couple the HPLC device with mass spectrometry. The method was tested with various mussel tissue samples. Received: 14 December 1995/Revised: 26 January 1996/Accepted: 30 January 1996     

聚苯乙烯—吡啶树脂的合成及催化水解反应

在氢氧化钠作用下，氯甲基化聚苯乙烯与吡啶反应制成聚苯乙烯－吡啶树脂，测定了其化学组成和红外光谱，并考察了在酯水解反应中的催化活性。     

1—酰基—4—氯环己烷与取代芳烃的区域与立体选择性反应

从环己烯合成了１－酰基－４－氯环己烷，发现在其在ＡｌＣｌ３催化与苯，氯苯，溴苯等优先生成反式１－芳基－４－酰基环己烷，与联苯反应时选择性较差。     

新显色剂对溴苯酚偶氮若丹宁光度法测定Au（Ⅲ）的研究

提出了以显色剂对溴苯酚偶氮若丹宁[5-(5-溴-2-羟基苯偶氮)若丹宁]作为光度法测定Au(Ⅲ)试剂的新方法。在1.2mol·L~(-1)盐酸介质及阴离子表面活性剂十二烷基苯磺酸钠(SDBS)存在下,Au(Ⅲ)与试剂形成桔红色配合物,545nm处有最大吸收,摩尔吸光系数ε为7.75×10~4,Au(Ⅲ)浓度在0～44μg/25ml范围内服从比耳定律。方法灵敏度高,选择性好,配合物的稳定时间长,操作简便,已成功地应用于含金废水中Au(Ⅲ)的测定。     

A comparison of polymerization characteristics and mechanisms of ε-caprolactone and trimethylene-carbonate with rare earth halides

Characteristics and mechanisms of the ring opening-polymerizations of ε-caprolactone (CL) and trimethylene carbonate (TMC) with rare earth halides have been compared for the first time. It has been found that rare earth halides show high catalytic activities for the polymerization of TMC, but very low activities for that of CL polymerization. The copolymerization of CL and TMC can proceed only in the presence of high contents of TMC in the comonomer feed. The copolymerization rate decreases rapidly with increasing molar fraction of CL in the feed. The mechanism study by IR, ¹H-, ¹³C-, and ³¹P-NMR spectra shows that the first step reaction of the polymerization of TMC or CL with rare earth halide is the complexation of monomer to the rare earth ion. The strong coordination of TMC to rare earth ion induces the ring-cleavage of TMC and generation of the cationic species, which initiate the polymerization of TMC via a cationic process. However, the polymerization of CL with rare earth halide is an “activated-hydrolysis” process, in which rare earth catalyst does not initiate the polymerization but serves as an activator of CL. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1339–1352, 1997     

Effects of poly(methyl methacrylate)-block-poly(vinyl acetate) copolymer on the spinodal decomposition of corresponding homopolymer blends

Effects of adding a small amount of poly(methyl methacrylate)-block-poly(vinyl acetate) (PMMA-b-PVAc) to poly(methyl methacrylate)/poly(vinyl acetate) (PMMA/PVAc) blends with a lower critical solution temperature (LCST) phase diagram on the kinetics of late-stage spinodal decomposition (SD) were investigated by time-resolved light scattering at 160°C. It is found that the coarsening process of the structure was slowed down or accelerated upon addition of PMMA-b-PVAc depending on the composition of the block copolymer and the blend. The effect of the block copolymer on the domain size were interpreted as compatibilizing and incompatibilizing effects of the block copolymer on PMMA/PVAc blends based on the evaluation of changes in the stability limits of PMMA/PVAc with the addition of block copolymer using random phase approximation (RPA).     

Stripping voltammetry of copper and lead using gold electrodes modified with self-assembled monolayers

One problem associated with using bare solid metal electrodes, such as gold and platinum, in stripping analysis to determine heavy metal ions such as lead and copper ions in dilute solutions is that underpotential deposition (UPD) gives multiple stripping peaks in the analysis of mixtures. These peaks are often overlapped and cannot be conveniently used for analytical purposes. Bifunctional alkylthiols, such as 3-mercaptopropionic acid, with an ionizable group on the other terminal end of the thiol can form self-assembled monolayers (SAMs) on the surface of the gold electrode. It is shown that such an SAM-modified gold electrode minimizes the UPD effects for the stripping analysis of lead and copper. The anodic peak potential shifts and the peak shape changes, indicating that the SAM changes the deposition and stripping steps of these heavy metal ions. Thus, the sensitivity levels for both single species and mixtures can be significantly improved for the conventional solid electrodes. The mechanism of the deposition reaction at the SAM-modified gold electrodes is discussed. Received: 29 May 1997 / Accepted: 24 June 1997