反相液相色谱质谱法分离鉴定3,4,6,7,9,10-6H-3,3,6,6-四甲基-9-对硝基苯基吖啶-1,8二酮

应用反相高效液相色谱法，分离和鉴定3，4，6，7，9，10－6H－3，3，6，6－四甲基－9－对硝基苯基吖啶－1，8－二酮（化合物Ⅰ），分离系统包括Zorbax SB C18及苯基柱，紫外检测器检测波长为285nm，等比和线性梯度淋洗，液相色谱－质谱联用和光导二极和列检测系统被用来鉴定主要化合物及其它杂质，此方法可达到分离效果好，灵敏度高。     

Combinational synthesis of oligonucleotides and assembly fabrication of oligonucleotide array

In this paper, a simple, reliable and flexible method, which integrated in situ synthesis with the spotting technique, was reported to fabricate oligonucleotide array. Different oligonucleotide sequences are synthesized on their relative code glass slides through combinational chemistry, thus the slides are broken into smaller pieces, in which the same code pieces have the same probe sequences. An oligonucleotide array is fabricated by arbitrarily assembling these different code pieces onto another solid substrate. In principle experimentation, four different sequences of P16 gene were synthesized and a 5 × 5 array including these four sequences and the control black was fabricated. The analysis results indicated that the hybridization fluorescence intensity of the same sequences locating different sets on the array gave the approximate values, and the fluorescence intensity ratio of matched sequence to one middle location base mismatched, two base mismatched, three middle base mismatched is (1.000 ± 0.080):(0.4991 ± 0.0671):(0.2360 ± 0.0044):(0.0493 ± 0.0033). Their relative accuracies were from 6.64 to 10.2%. This result might be used to rapidly screen single-nucleotide polymorphisms (SNPs).     

交替三线性分解算法与反相高效液相-二极管阵列检测方法相结合同时测定苯二酚的位置异构体

 利用交替三线性分解算法与反相高效液相 二极管阵列检测 (RP HPLC DAD)相结合 ,在洗脱时间为1 0 86min～ 1 399min(间隔 1 / 1 50min)、紫外吸收波长为 2 68nm～ 2 98nm(间隔 1nm)时对苯二酚位置异构体的重叠及光谱体系进行了分辨研究。分辨结果与实际结果一致。同时测定了水溶液中共存的邻苯二酚、间苯二酚和对苯二酚的含量 ,回收率分别为 (1 0 0 1± 1 0 ) % ,(99 4± 1 4) % ,(1 0 0 5± 1 7) %。研究结果表明 :该方法定量快速准确 ,实验操作步骤简单 ,解决了在干扰物存在条件下三者很难同时分辨的问题。     

孔性氧化铝模板与一维纳米新材料的制备

纳米材料尤其是以碳纳米管有序阵列为代表的一维纳米阵列材料的重要价值,促进了人们对模板合成方法的研究。本文简要回顾和总结了近年来有关孔性氧化铝模板的制备及其应用的研究进展,结合我们实验室的部分相关研究工作,揭示了孔性氧化铝模板在合成与组装一维纳米新材料方面的重要作用,以进一步活跃和促进该重要领域的研究和发展。     

Approximate expressions and the relationship between pyramidalization (out‐of‐plane deformation) characteristics of trigonal centers

Fairly accurate approximate expressions for commonly used characteristics of non‐planarity of trigonal sp²‐hybridized centers are reported. It is shown that the behavior of all these parameters as a function of bond angles (α, β, γ) is determined primarily by the square‐root of the difference [360° ? (α + β + γ)]. This quantity is proposed as a new versatile measure of pyramidalization. © 2012 Wiley Periodicals, Inc.     

Discrimination of Lung Cancer Related Volatile Organic Compounds with a Colorimetric Sensor Array

A simple and rapid discrimination of four lung cancer related volatile organic compounds (VOCs) was achieved with a novel colorimetric sensor array. Based on the cross-responsive mechanism, the sensor system exhibited high sensitivity to selected lung cancer biomarkers, including p-xylene, styrene, isoprene, and hexanal with concentrations varying from 50 ppb to 500 ppb. By extracting color information, it provided good selectivity and fine discrimination of selected gases via pattern recognition with Fisher linear discriminant (FLD). Additionally, with the employment of the Takagi-Sogeno Fuzzy Neural Network (TSFNN), different concentrations of selected VOCs were discriminated. It also suggested that the colorimetric sensor array proposed could not only distinguish different lung cancer related VOCs but also discriminate specific VOCs of different concentrations with an average rate of classification up to 95%. Our preliminary study demonstrated that the cross-responsive sensor array had infinite potential for further clinical and commercial use for early diagnosis of lung cancer.     

Determination of Bioactive Components of Cistanche deserticola (Roucongrong) by High-Performance Liquid Chromatography with Diode Array and Mass Spectrometry Detectors

Cistanche deserticola (Orobanchaceae) has been widely used in China for food and medicinal purposes. Chemical differentiation between the raw and steamed C. deserticola was performed by high-performance liquid chromatography coupled with diode array detection and mass spectrometry. Eight chemicals (echinacoside, cistanoside A, acteoside, cistanoside C, 2′-acetylacteoside, isoacteoside, isocistanoside C, and tubuloside B) were obtained from raw and steamed C. deserticola, and the kinetics in the steaming process were investigated in detail. When the steaming time increased, the concentrations of echinacoside, cistanoside A, acteoside, cistanoside C, and 2′-acetylacteoside decreased, while the levels of isoacteoside, isocistanoside C, and tubuloside B increased. Furthermore, two compounds, 5-hydroxymaltol and 5-hydroxymethylfurfural, were found only in the steamed form. In addition, hierarchical clustering analysis and principal component analysis were performed to evaluate the classify the chemical concentrations among steamed C. deserticola. The results showed that steaming had a significant influence on the chemical constitution. The study provide chemical analysis of raw and steamed C. deserticola, including possible transformation pathways, and should allow better understanding of the steaming process of this herb.     

Solid-phase extraction using a molecularly imprinted polymer for the selective purification and preconcentration of norfloxacin from seawater

Abstract

A highly selective and effective method for the purification and preconcentration of norfloxacin (NFX) in seawater samples was developed based on molecularly imprinted solid-phase extraction (MISPE). The molecularly imprinted polymer was synthesized by precipitation polymerization. Methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) were used as the functional monomer and crosslinker, respectively. The resulting molecularly imprinted polymer (MIP) showed high adsorption for NFX and was selective for its solid-phase extraction. An offline MISPE method followed by high performance liquid chromatography with diode array detection was established for the determination of NFX in seawater. The recoveries of spiked seawater samples using the MISPE columns were satisfactorily higher than 77.6%. The relative standard deviation was less than 5.60%, and the limit of detection was 0.027?μg L^?1. Four seawater samples obtained from the Bohai Sea were analyzed, and NFX was found only at one location at a concentration of 0.280?μg L^?1.     

Analysis of Commercial Multi-vitamin Preparation by HPLC with Diode Array Detector

Abstract

A simple and efficient HPLC analysis method has been developed to simultaneously analyse complicated multi-vitamin preparations, including vitamin B complexes, vitamin C, orotic acid, methionine, calcium pantothenate, nicotinamide, biotin, folic acid and rutin, without using expensive ion pairing reagent. Diode array detector and adjustment of the mobile phase to pH 5.6 are required in the study. This method has been validated with good linearity, reproducibility, recovery and accuracy for analysis of commercial multi-vitamin products.     

Simplified Solid-Phase Extraction Procedure and Liquid Chromatographic Determination of Celecoxib in Rat Serum

A simplified solid phase extraction method, eliminating a preliminary protein precipitation has been developed for the determination of celecoxib in rat plasma. The technique included a solid phase extraction of the serum samples on a [poly (divinylbenzene-co-N-vinylpyrrolidone)] sorbent. After conditioning, the cartridge was loaded with 0.5 mL of acidified serum containing internal standard. Elution was made with 1 mL of a mixture of acetonitrile and methanol (1/1, v/v). After evaporation of the eluate to dryness and reconstitution with methanol, the samples were analyzed on an octadecyl bonded phase with several mobile phases containing acetonitrile and a phosphate buffer. Detection was carried out using a Photodiode Array Detector. Full validation of the proposed method was provided (linearity range: 0.01–2 mg. L^–1, average extraction efficiency: 92.4%; average intra-day variability: 4.6% with an accuracy of 94.8%; average interday variability: 5% with an accuracy of 95.3%, limit of detection: 0.005 mg. L^–1, limit of quantification: 0.002 mg. L^–1). The proposed method was successfully utilised to quantify celecoxib in rat plasma for a pharmacokinetic study.Revised: 26 January and 23 April 2004