清除树脂是一种特殊的固相试剂。近五年，它们被广泛的用于平行液相法合成组合化学库，简化液相组合化学库的纯化操作。本文综述了清除树脂在纯化操作中的使用策略。根据清除纯化原理，介绍了共价键型和离子键型两类清除树脂。给出了清除树脂在组合化学中的具体应用实例。最后对清除树脂的发展作了展望。

以聚四氟乙烯纤维为基体通过60Co辐射引发与丙烯酸接枝制备弱酸性阳离子交换纤维。产物功能基含量为3.06mmol/g，在pH=5时该纤维达到对Cu2+的最大动态吸附量为107.48mg/g。使用不同浓度HCl对饱和吸附铜的接枝纤维进行洗脱，证实该纤维对铜离子具有优异的解吸性能。

M icrow ave assisting the addition reaction of Wang resin bound secondary a mine 1 and isocyanatew as carried out for the first time. The reaction time coursew as determ ined by analyzing FT IR spect raob tained using the improved KB rpellet method by grinding down the resin beads priorto recording. The resu It s show ed that the react ion assisted by m icrow ave was accomp lished only in 12min, while the reaction without microw ave was completed in 210min.

Polymer-supported quininium, cinchoninium and cinchonidinium salts were used as phase transfer catalysts for the asymmetric C-alkylation of N-diphenylmethyleneglycine t-butyl ester in the synthesis of chiral phenylalanine, alanine, valine and 2-aminopent-4-enoic acid. The influence of the alkylation conditions on the chemical yields and the enantiomeric excesses were studied. The highest enantiomeric excess obtained was 27%. Although the enantiomeric excesses obtained in the present work are lower than those obtained in the corresponding non-supported reactions, they are nevertheless significantly higher than those obtained in most other polymer-supported phase transfer catalysed asymmetric syntheses so far reported in the literature.

of 0.01-50% v/v HCl, its sorption onto the surface of the PTFE fiber in the microcolumn, elution with 3% m/v KBH4 in 0.5% m/v KOH, hydride generation with 15% v/v HCl solution and determination with atomic fluorescence spectrometry. The alkaline KBH4 solution was employed not only as an efficient eluent but also as the reductant to produce selenide anion for subsequent hydride generation. With a consumption of 12.4ml of sample solution, a detection limit (3δ) of 4ng l-1 was achieved at a sample throughput of 26 samples h-1. The retention efficiency was 67%, being five times that obtained with a PTFE knotted reactor (KR). The linear ranges of the diagrams of signal intensity against sample loading flow rate, and sample loading time, were much wider than those achieved with a KR, offering more potential for obtaining high sensitivity by increasing sample loading rates and/or sample loading time. The precision for 11 replicate measurements of 0.5µg l-1 Se (IV) was 1.5% (RSD). The recoveries of Se (IV) from natural water samples varied from 96 to 108%. The concentration of Se (IV) in a certified reference material (NASS-5, sea-water) determined by the present method with a simple aqueous standard curve calibration was in good agreement with the certified value. The developed method was also successfully applied to the detection of Se (IV) in local river water, lake water and sea-water samples.

The polytetrafluoroethylene fiber grafted acrylic acid was used as a cation exchanger. The exchange capacity of the cation fiber is 3.06mmol/g. The maximum Cu2+ adsorption capacity is 107.48mg/g. It could be desorbed completely by 1mol/L HCl.

A general method for the solid phase synthesis of hydro-uracils and thiouracils is described. Resino ester 2 reacts with various primary amines to give secondary amines 3, which are converted to the resino ureas (thioureas) 4 by treatment with isocyanates (isothiocyanates). Prepa-ration of the hydro-uracils and thiouracils 5 is achieved by acidic cyclization-cleavage from the resin. The synthesis is designed to be amenable for structure based library approach to photosys-tem II D1 protein inhibitors.

Since highly crystalline poly (L-lactide) (PLLA) degrades rather slowly in a biological environment and the crystalline domains remaining after partial degradation of the implant material give rise to an inflammatory response of the surrounding tissue, L-and D, L-lactide copolymer [P(L-DL)LA] having a low crystallinity is preferred in surgical applications. The thermal transitions and the mechanical properties of P (L-DL) LA rods were discussed in this paper. It was found that the self-reinforced P (L-DL) LA [SR-P(L-DL)LA] was strong enough in terms of mechanical properties compared with the self-reinforced PLLA [SR-PLLA].

In this work, acrylic acid grafted PTFE fibers were prepared as a new packing material for flow injection (FI) on-line microcolumn preconcentration coupled with flame atomic absorption spectrometry (FAAS) for determination of trace lead and cadmium in environmental and biological samples. Effective preconcentration of trace cadmium and lead was achieved in a pH range of 3.5-6.5 on a microcolumn packed with the developed new packing material. The retained lead and cadmium were efficiently eluted, respectively, with 1.0mol/l HNO3 and 0.5mol/l HCl for on-line FAAS determination. The developed sorbent exhibited fairly fast kinetics for the adsorption of Pb (II) and Cd (II), permitting the use of high sample flow rates up to at least 10.8ml/min for the FI on-line microcolumn preconcentration system without loss of the retention efficiency. With a preconcentration time of 45 s at a sample loading flow rate of 10ml/min, the enhancement factor was found to be 49 for Pb and 73 for Cd at a sample throughput of 55h−1. The detection limits (3σ) was 0.26 and 0.10μg/l for Pb and Cd, respectively. The precision (RSD) for 11 replicate measurements was 1.9% at the 25μg/l Pb level, and 0.9% at the 10μg/l Cd level. The developed method was successfully applied to the determination of trace Pb and Cd in a variety of environmental and biological samples.