化學(xué)

來源出版物：SCIENCE CHINA Chemistry， 2015， 58（1）： 174-179聯(lián)系郵箱：Mingshu Chen， chenms@xmu.edu.cn

封面介紹：The cover picture shows the synthesis of carboxylatopillar［5］arene-modified reduced graphene nanosheets（RGO-CP5）capable of molecular recognition. They exhibited much better water-dispersibility and enhanced fluorescence-quenching property as compared with native RGO， which can be used to detect analytes. More details are discussed in the article by Yang et al. on page 125-130.

Carboxylatopillarene-Modified Reduced Graphene Oxides with High Water Dispersibility for Fluorescent Dye Sensing

Ting Zhou， Hao Yu， Mingqiang Liu， et al.

Abstract： Carboxylated pillar［5］arene（CP5）macrocycles were modified onto the surface of reduced graphene oxide（RGO）via covalent bonds to form new pillarene-functionalized RGO nanosheets， i.e.， RGO-CP5. The obtained RGO-CP5 nanosheets capable of molecular recognition exhibited much better water-dispersibility and enhanced fluorescence-quenching property as compared with native RGO. This new sensing platform holds great potentials in the sensing and detection of analytes， such as organic dye molecules and pesticides， in aqueous solutions.

Keywords： dye molecule； fluorescence quenching； nanosheets； pillarene； reduced graphene oxide

來源出版物：Chinese Journal of Chemistry， 2015， 33（1）： 125-130聯(lián)系郵箱：Ying-Wei Yang， ywyang@jlu.edu.cn

柱前衍生高效液相色譜-熒光檢測(cè)法測(cè)定水稻中7種巰基化合物

周蓉，曹趙云，牟仁祥，等

建立了水稻中半胱氨酸（Cys）、谷胱甘肽（GSH）和植物螯合肽（phytochelatin，PC：PC2、PC3、PC4、PC5、PC6）7種巰基化合物的柱前衍生高效液相色譜-熒光檢測(cè)分析方法.樣品經(jīng)0.1%三氟乙酸（TFA）（含6.3 mmol/L二乙烯三胺五乙酸（DTPA））超聲提取，然后以單溴二胺（mBrB）為衍生劑在pH 8.0的4-羥乙基哌嗪丙磺酸（HEPPS）緩沖溶液中衍生化.采用的色譜分離柱為Agilent Eclipse plus Cl8柱，流動(dòng)相為0.1%TFA（pH2.5）和100%乙腈（ACN），梯度洗脫，流速為0.8 mL/min.熒光檢測(cè)的激發(fā)波長(zhǎng)和發(fā)射波長(zhǎng)分別為380 nm和470 nm.結(jié)果表明，7種巰基化合物在0.7～100.0 mg/L范圍內(nèi)，峰面積與質(zhì)量濃度之間的線性關(guān)系良好（r2≥0.9991）；檢出限為0.03～0.20 mg/L；加標(biāo)回收率為89.26%～99.42%，相對(duì)標(biāo)準(zhǔn)偏差為 2.05%～5.87%.該方法準(zhǔn)確、靈敏度高、重現(xiàn)性好，為水稻中巰基化合物的研究提供了檢測(cè)手段.

柱前衍生；高效液相色譜法；巰基化合物；水稻

來源出版物：色譜， 2015， 33（1）： 35-39聯(lián)系郵箱：陳銘學(xué)，cmingxue@163.com

封面介紹：The cover describes an efficient experimental setup for the temperature-programmed reaction of CO oxidation on supported catalysts. Two liquid nitrogen traps are used to remove water and the formation carbon dioxide. Hence， the conversion of CO can be monitored on-line by a gas-chromatography using a TCD detector. This setup is capable to measure CO conversion rate as a function of the reaction temperature， and easily compare the relative activities on the various initial states. A Fourier transform infrared spectroscopy can be combined to in-situ measure the surface active species（see the article by Xuefei Weng， Xiang Yuan， Huan Li， Xiaokun Li， Mingshu Chen & Huilin Wan on page 174-179）.

The study of the active surface for CO oxidation over supported Pd catalysts

Xuefei Weng， Xiang Yuan， Huan Li， et al.

CO oxidation was investigated on various powder oxide supported Pd catalysts by temperature-programmed reaction. The pre-reduced catalysts show significantly higher activities than the pre-oxidized ones. Model studies were performed to better understand the oxidation state， reactivities and stabilities of partially oxidized Pd surfaces under CO oxidation reaction conditions using an in situ infrared reflection absorption spectrometer（IRAS）. Three O/Pd（100）model surfaces， chemisorbed oxygen covered surface， surface oxide and bulk-like surface oxide， were prepared and characterized by low-energy electron diffraction（LEED）and Auger electron spectroscopy（AES）. The present work demonstrates that the oxidized palladium surface is less active for CO oxidation than the metallic surface， and is unstable under the reaction conditions with sufficient CO.

CO oxidation； in-situ IRAS； temperature-programmed reaction； palladium； catalytically active surface