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991.
The use of a laboratory-made iodide ion-selective electrode with tubular configuration and based on a crystalline membrane (AgI/Ag2S) as the detector for ion chromatographic determination of iodide in urine and serum is described. A CIS reversed-phase column was coated withN-cetylpyridinium chloride to prepare a low-exchange-capacity analytical column and with hexadecyltrimethylammonium bromide to prepare a concentrator pre-column. A 2.0 ml min–1 flow rate of deionized water and 0.1 mol 1–1 KNO3 solution was used for the pre-concentration and for the chromatographic separation, respectively. For optimum performance of the detector a background level of iodide was added into the column effluent. A linear relationship (r = 0.9997) between tubular electrode potential (as peak height) and iodide concentration in the range 5–400 g 1–1 and a detection limit of 1.47 g 1–1 were obtained. The method shows good reproducibility for both peak height (2.2% RSD) and retention time (1.3% RSD). Recoveries on its application to the samples were 93.0–100.9% for urine and 91.4–106.0% for serum. 相似文献
992.
Si-Tai Zheng Huan-Huan Yin Zhao-Guang Ma Nan-Li Sheng Tian-Guang Zhan Xiao-Yang Yan Jiecheng Cui Li-Juan Liu Kang-Da Zhang 《中国化学快报》2019,30(3):707-709
Photoresponsive supramolecular hydrogel was fabricated from a small azobenzene-bridged dicationic pyridinium salt in the aqueous solution. The UV-vis light triggered reversible gel-sol transformation of such low-molecular-weight supramolecular hydrogel was systematically investigated through various analytical techniques. 相似文献
993.
ClnOPodiumpoIycePhalum(VantjCYWhetHsuancalled'DuanXielin'inChineseisusedinfolkmedicineforthetreatInentofhaemorrhagiadisease.lInordertofmdtheactivecomPounds,studiesonthechedricalconstituentsofthewholeplan,collectedatHuoShanofAnhuiprovince,werecarriedout.Fromthealcoholicextracts,wehaveisolatedanewanthraquinone,Glyceroyl-l,6,8-trihydroxy-3-methyl-9)lO-dioxo-2-anthrcenecarboxylateI(Figurel).Iwasobtainedasredneedles,mP:ll9-l2l"C.TheHR-MSdareaffordedthefor-mulaasCl9Hl6O9(Found388.O791;… 相似文献
994.
Li Qiu WANG Xiao Jun PENG* Rong ZHANG Guo Quan XU Jing Nan CUI State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 《中国化学快报》2003,(1)
Indocyanine dyes as fluorescent labeling reagents have been used in bioanalysis1,2. Arylsulfonate indocyanine dyes 1d and 1e developed by Waggoner A. S. et al.3,4 have excellent fluorescent properties combined with good aqueous solubility, are a new generation of fluorescent label compounds for proteins, oligonucleotides and other compounds containing hydroxyl, mercaptol or primary amine groups5. However, photostability of these dyes has been a problem. Z. G. YAO et al.6 reported that p… 相似文献
995.
利用程序升温电导法(TPEC)和程序升温还原法(TPR),研究比较了还原气氛下Pt/MoO_3和Pt/Co_3O_4体系中不同类型的半导体氧化物和吸附氢之间电荷和物种交换的规律.发现微量Pt通过吸附解离H_2成为原子氢,在较低温度下大大加快n型半导体氧化物MoO_3和氢之间电子传递速度,显著地降低MoO_3的还原温度,但在同样条件下却不能有效地活跃p型半导体氧化物Co_3O_4和氢之间的电子传递,因而不能明显地促进Co_3O_4的还原.导致此现象的原因,可能与不同类型的半导体导电机构不同而引起的对氢的敏感程度不同有密切关系. 相似文献
996.
997.
998.
量子点标记链霉亲和素及其生物活性检测 总被引:2,自引:0,他引:2
选用无机盐为前驱体,在水相中合成CdTe量子点,并用此量子点标记链霉亲和素,通过SephadexG-100层析分离纯化量子点标记的链霉亲和素,采用磁颗粒标记的链霉亲和素与量子点标记的链霉亲和素竞争结合辣根过氧化酶标记的生物素,即酶联免疫竞争抑制分析法检测链霉亲和素标记量子点后的生物活性,计算约70.3%的链霉亲和素标记到量子点上,且具有生物活性。每毫克量子点大约可偶联0.14 mg的链霉亲和素。采用荧光光谱研究量子点标记前后的荧光变化,标记后量子点的最大发射波长蓝移了8 nm,而发射光谱的半峰宽基本不变,说明量子点与链霉亲和素结合后粒子没有团聚,分散性好。 相似文献
999.
Shao-hua Huang Zheng-wu Bai Chuan-qi Yin Shi-rong Li 《高分子科学》2006,(2):107-114
Two polyurethanes of different molecular weights were prepared by the copolymerization of phenyl diisocyanate and diisopropyl tartrate. The polyurethanes having terminal isocyanate groups were reacted with 3-aminopropyl silica gel to afford two chiral stationary phases. The Mn of the two polyurethanes were 4057 g/mol and 6442 g/mol. The polyurethanes and the corresponding chiral stationary phases were characterized by FT-IR, 1H NMR and elemental analysis. The loading capacities of the polyurethanes on silica gel were 0.68 mmol units/g and 0.61 mmol units/g, respectively. The separation performance and the influence of additives, triethylamine and trichloroacetic acid, on the separation of chiral compounds were investigated by HPLC. The chiral stationary phase prepared from polyurethane with Mn of 4057 g/mol demonstrated better enantioseparation capability than that with Mn of 6442 g/mol. Additionally, it was found that the addition of triethylamine and trichloroacetic acid in the mobile phases significantly improved the enantioseparation for these two chiral stationary phases. 相似文献
1000.
Background Pillar[n]arene(PA[n])contains a symmetrical structures,where para-bridge connection between the units looks like a column-like or pillar shape and polygonal structure from side and top views,respectively.The attached groups to the PA[n]are pointing towards the opposite directions along the columnar axis. 相似文献