用光谱探针研究β-环糊精与DHA包结物的制备及对DHA稳定性影响

以酚酞作为光谱探针 ,采用紫外 -可见光谱法研究了在pH =10 .5的缓冲液中 β -环糊精与DHA包结物的制备 ,结果表明 ,1分子DHA与 3分子 β -环糊精依据范德华作用力和疏水作用力发生包结作用 ,生成稳定的包结物。包结物适宜的制备条件为 :β -环糊精与DHA的摩尔比为 3∶1,主客体溶液的浓度比为12 .5∶1;包结温度 2 8℃ ;反应时间 2 .2h。多种弱相互作用力协同作用于 β -环糊精的配位包结过程 ,主 -客体间的尺寸匹配决定所形成包结物的稳定性 ,根据竞争包结理论 ,用Hidebran -Benesi方程测定了 2 5℃条件下的包结物稳定常数为 9.2 6× 10 13L/mol,包结物稳定。包结物中DHA的氧化稳定性得到显著改善。     

氧瓶燃烧法测定Si-69的全硫含量

采用氧瓶燃烧法测定双-(γ-三乙氧基硅基丙基)四硫化物(Si-69)的全硫含量,以过氧化氢溶液为吸收液,酚酞为指示剂,用氢氧化钠标准溶液直接滴定。探讨了该方法的精密度和准确度。结果表明,方法的相对标准偏差(RSD)<2%,与国标方法无显著性差异,相对误差≤2%。该方法简便、准确、成本低,还有快速的优点,可用于Si-69的全硫质量控制分析。     

Active pharmaceutical ingredients detected in herbal food supplements for weight loss sampled on the Dutch market

Herbal food supplements claiming to reduce weight may contain active pharmacological ingredients (APIs) that can be used for the treatment of overweight and obesity. The aim of this study was to determine whether herbal food supplements for weight loss on the Dutch market contain APIs with weight loss properties. Herbal food supplements intended for weight loss (n = 50) were sampled from August 2004 to May 2013. An HPLC-DAD-MS/MS method was used to screen for the presence of the APIs in herbal supplements. In 24 samples the APIs sibutramine, desmethylsibutramine (DMS), didesmethylsibutramine (DDMS), rimonabant, sildenafil and/or the laxative phenolphthalein were identified 41 times. The presence of these APIs was, however, not stated on the label. The potential pharmacological effects of the detected APIs were estimated using data from reported effective doses of approved drugs. Use of 20 of the 24 herbal food supplements may result in potential pharmacological effects. Furthermore, risk assessment of phenolphthalein, a suspected carcinogen and found to be present in 10 supplements, based on the margin of exposure (MOE) approach, resulted in MOE values of 96–30 000. MOE values lower than 10 000 (96–220) were calculated for the daily intake levels of four out of these 10 supplements in which phenolphthalein was found. However, taking into account that weight loss preparations may be used for only a few weeks or months rather than during a lifetime, MOE values may be two to three orders of magnitude higher. The current study shows that the use of food supplements with sibutramine, DMS, DDMS and/or phenolphthalein could result in pharmacological effects.     

硝酸铵-钼酸铵-微晶酚酞体系分离富集铅(Ⅱ)

Pb²⁺作为一种具有生物蓄积毒性的重金属离子,严重危害着环境和人体健康,微痕量Pb²⁺的分离富集工作一直是研究热点。固相萃取技术虽能够获得较高的富集率,但材料的制备较为繁琐,应用上受到了限制。实验利用钼酸铵作为微痕量Pb²⁺的沉淀剂,建立了一种以微晶酚酞作吸附剂分离富集微痕量Pb²⁺的方法。分别考察了钼酸铵溶液的用量、酚酞溶液用量、酸度、盐的类型及用量、吸附温度、吸附时间、Pb²⁺的初始浓度对富集率的影响。结果表明,当体系中Pb²⁺的含量为100 μg时,控制体系的pH=3~7,加入1.0 mL 5.0×10^-4 mol/L钼酸铵溶液,1.0 g 硝酸铵,0.3 mL 70 g/L酚酞乙醇溶液,震荡摇匀后,静置10 min,Pb²⁺与钼酸铵反应生成的离子缔合物被定量吸附到微晶酚酞表面上,从而实现了微痕量Pb²⁺的分离富集。方法成功应用于合成水样中微痕量Pb²⁺的定量分离,富集率在95%～105%,能够满足微痕量Pb²⁺的分离富集要求。     

核磁共振法测定酚酞聚芳醚腈的分子量

功地合成了带烷端基的酚酞聚芳醚腈 ,测定其 1H- NMR谱 ,根据链中芳环质子共振峰与链端基质子共振峰积分强度比求解分子量 ,与聚合物特性粘度关联 ,确定了酚酞聚芳醚腈在四氢呋喃溶剂中 ,6 0℃的 Mark- Houwink常数 K=1.6 4× 10 -6,α=0 .918,建立了其在四氢呋喃溶剂中的特性粘度与数均分子量的关系 :[η]=1.6 4× 10 -6M0 .918     

酚酞基聚醚砜溶解度参数的测定

采用浊度滴定法测定和基团贡献法估算了酚酞基聚醚砜的溶解度参数。基团贡献法估算与浊度滴定法测定的结果相吻合。测得酚酞基聚醚砜的溶解度参数为20.76J1/2mL-1/2,这对研究其溶液性质和应用有重要的意义。     

Reinforced effect of wollastonite on phenolphthalein poly(ether ketone)

The mechanical properties of wollastonite-filled phenolphthalein poly-(ether ketone) (PEK-C) composites have been studied at room temperature and 200°C. The dispersion of wollastonite particles in PEK-C matrix were investigated by means of scanning electron microscope. The modulus and strength of the composites increased with filler content. The reinforced effect of wollastonite on PEK-C is more marked at elevated temperature. The glass transition temperature of the composites is higher than that of PEK-C and is independent of filler content. The restriction effect of filler particles on the molecular mobility of the polymer matrix should be attributed to the reinforcement. © 1997 John Wiley & Sons, Inc. J Appl Polym 65: 649–653, 1997     

酚酞环氧树脂的合成研究

在碱金属盐K2CO3/H2O催化下,由酚酞和环氧氯丙烷缩聚制得了低分子量酚酞环氧树脂。用红外光谱表征了其分子结构,测定了酚酞环氧树脂的环氧值。讨论了单体的摩尔比、催化剂用量、水含量及反应温度对产物环氧值的影响。结果表明:在实验范围内,改变酚酞与环氧氯丙烷的摩尔比(1∶10～1∶4)或酚酞与催化剂的摩尔比(1∶2～1∶1),均可得到低分子量的酚酞环氧树脂。     

DMFCs用磺化聚醚醚酮/磺化酚酞型聚醚砜共混质子交换膜

A sulfonated poly(ether ether ketone) (SPEEK) membrane with fairly high degree of sulfonation (DS) swells excessively and even dissolves at high temperature. To solve these problems, sulfonated phenolphthalein poly(ether sulfone) (SPES-C, DS 53.7%) is blended with the SPEEK matrix (DS 55.1%, 61.7%) to prepare SPEEK/SPES-C blend membrane. The decrease in swelling degree and methanol permeability of the membrane is dose-dependent. Pure SPEEK (DS 61.7%) membrane dissolves completely in water at 70ºC, whereas the swelling degree of the SPEEK (DS 61.7%)/SPES-C (40%, by mass) membrane is 29.7% at 80ºC. From room temperature to 80ºC, the methanol permeability of all SPEEK (DS 55.1%)/SPES-C blend membranes is about one order of magnitude lower than that of Nafion®115. At higher temperature, the addition of SPES-C polymer increases the dimensional stability and greater proton conductivity can be achieved. The SPEEK (DS 55.1%)/SPES-C (40%, by mass) membrane can withstand temperatures up to 150ºC. The proton conductivity of SPEEK (DS 55.1%)/SPES-C (30%, by mass) membrane approaches 0.16 S&#8226;cm－1, matching that of Nafion&#61650;115 at 140ºC and 100% RH, while pure SPEEK (DS 55.1%) membrane dissolves at 90ºC. The SPEEK/SPES-C blend membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.     

ATS／PEK—C共混物的相容性及其相分离

本文用动态力学扭辫分析(TBA)和扫描电镜(SEM)研究了乙炔端基砜(ATS)和酚酞型聚醚酮(PEK-C)共混物的相容性和相分离的行为特征.未固化ATS/PEK-C共混物为相容体系,ATS加入使PEK-C的Tg降低,共混物的Tg与ATS/PEK-C组成比有关.共混物在固化过程中发生相分离而形成两相结构,相分离程度与固化条件有关。