Technique for Monolithic Fabrication of Microlens Arrays Integrated with Infrared CCD

Based on scalar diffraction theory, 8-phase-level 256×256 elements diffractive microlens array with element dimension of 50×33 μm2 have been fabricated on the back-side of PtSi(3～5 μm) infrared CCD. The measurement results indicated that the ratio of the signal-to-noise of the infrared CCD with microlens was increased by a factor of 2.8.     

Poly(methacrylic acid-ethylene glycol dimethacrylate) monolith in-tube solid-phase microextraction applied to simultaneous analysis of some amphetamine derivatives in urine by capillary zone electrophoresis

A method based on in-tube solid-phase microextraction and capillary zone electrophoresis (CZE) was proposed for simultaneously determining four amphetamines (amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, and 3,4-methylenedioxymethamphetamine) in urine. A poly(methacrylic acid-ethylene glycol dimethacrylate) monolithic capillary column, which can provide sufficient extraction efficiency, was introduced for the extraction of amphetamines from urine samples. The hydrophobic main chains and acidic pendant groups of the monolithic column make it a superior material for extraction of basic analytes from aqueous matrix. After extraction, the samples were analyzed by CZE. The best separation was achieved using a buffer composed of 0.1 M disodium hydrogen phosphate (adjusted to pH 4.5 with 1 M hydrochloric acid) and 20% methanol v/v, with a temperature and voltage of 25 degrees C and 20 kV, respectively. By applying electrokinetic injection with field-amplified sample stacking, detection limits of 25-34 microg/L were achieved. Excellent method of reproducibility was found over a linear range of 0.1-5 mg/L. Determination of these analytes from abusers' urine sample was also demonstrated.     

基于金属介导和离子液体的新型绿原酸印迹整体柱的制备及评价

选用1-乙烯基-3-乙基咪唑四氟硼酸盐([VElm]BF4,一种离子液体)作为功能单体,以Co2+为介导离子,结合1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)/二甲基亚砜(DMSO)二元致孔体系制备了绿原酸印迹整体柱。经过对制备参数的考察,确定最佳比例为绿原酸:Co2+:[VElm]BF4:EDMA(乙二醇二甲基丙烯酸酯)(摩尔比)=1:1:5:20,[BMIM]BF4:DMSO=3:1(V/V),最大印迹因子达2.10。通过优化色谱条件,最终在乙腈:20 mmol/L乙酸钠缓冲液(pH 4.2)=70:30(V/V)时实现了绿原酸及其类似物的完全分离。由此可见,以离子液体为功能单体及致孔剂,在金属介导策略下制备的分子印迹聚合物可实现绿原酸的特异性识别及分离。     

有机聚合物整体柱及其在生物大分子色谱分离中的应用

整体柱是近年发展起来的一种新型的色谱分离分析技术，与传统的色谱柱相比，具有制作简单、背压低、分辨率高、柱容量大等优点。本文介绍了有机聚合物整体柱及其在生物大分子色谱分离领域的应用，分析了其存在的问题，并展望了其应用前景。     

One-Step Synthesis of Monolithic Silica Nanocomposites in Fused Silica Capillaries

The ideal way to prepare efficient, yet robust stationary phases for microanalytical high-resolution methods such as capillary chromatography and electrochromatography remains to be defined. In this contribution a one step sol-gel process is proposed for the production of monolithic, macroporous nanocomposite phases in fused silica capillaries, which require no additional derivatization, since they already bear the interactive (C8) moieties. The effect of the catalyst, the water content, the pH, as well as that of certain additives on monolith formation and porosity is investigated. Volume shrinkage and a tendency to crack were the major obstacles to overcome. Homogeneous stationary phases could be produced by applying a pH gradient during sol formation, thereby changing the catalytic principle from acidic (0.1 M HCl) to basic (gradual formation of OH^– as a consequence of the hydrolysis of N-methylformamide). Gelation/coacervation of suchgels could be induced by the addition of N,N-diethylamine. The water content during sol formation was determined as decisive for pore formation, with 250% of the amount theoretically needed for complete hydrolysis of all precursors giving optimal results. The volume shrinkage problem during xerogel formation was resolved by integrating dialkyldialkoxysilane units (dimethyldiethoxysilane 35 mol%) into the silica network.     

Detection of single nucleotide polymorphisms using electrospray ionization mass spectrometry: validation of a one-well assay and quantitative pooling studies

Single nucleotide polymorphisms (SNPs) are currently being mapped and databased at a remarkable pace, providing a viable means for understanding disease susceptibility, differential drug response and human evolution. Consequently, there is an increasing demand for SNP genotyping technologies that are simple, rapid, cost effective and readily amenable to automation for high-throughput analyses. In this study, we improved the Survivor Assay, a SNP detection method based on electrospray ionization mass spectrometry (ESI-MS), with several developments. One improvement is the development of a one-well assay, requiring no off-line purification of the polymerase chain reaction product, achieved by simple addition of reagent solution into a single well. Another is the on-line separation of magnesium and dideoxynucleotides using an in-house made monolithic metal chelating column, eliminating any off-line sample preparation prior to mass spectrometric analysis. Here the Survivor Assay is extended from a proof-of-principle concept to a validated method by genotyping six SNPs from five different regions of human genomic DNA in 55 individual samples with 100% accuracy. This improved Survivor Assay eliminates the tedious and time-consuming steps of sample preparation, minimizes sample handing and offers a high-throughput analysis of SNPs by ESI-MS. The current combined preparation and analysis time is 2 min per sample. The simplicity of this method has potential for full automation and parallel chromatography and, thus, reduced analysis time. In addition, we have adapted the Survivor Assay for quantitative SNP analysis in pooled DNA samples. The capabilities and sensitivity of this approach were evaluated. We demonstrate that an allele occurring at a frequency of 2% can consistently be quantitated.     

混合模式硅胶基质毛细管电色谱整体柱的制备及其电色谱性能研究

采用温和条件下的溶胶-凝胶技术，成功制备了阴离子交换-反相混合模式硅胶基质毛细管电色谱整体柱。通过调整反应液中不同前体的比例，优化了整体柱的制备条件。通过扫瞄电镜，对柱床进行了表征和分析。实验发现，所制备的整体柱电渗流的方向和大小可随流动相pH值的改变而改变，在酸性和中性条件下，具有从阴极流向阳极的电渗流；当流动相pH值升至约7．5时，电渗流方向发生了反转（由阳极流向阴极）。在优化的实验条件下，用所制备的整体柱对所考察的酸性（中性）化合物实现了快速分离，并获得了高达160，000N／m的柱效。     

Catalytic Combustion of Methane over CO1-xMgxO/Al2O3/FeCrAl Monolithic Catalysts

A series of CoxMgxO/Al2O3/FeCrAl catalysts （x=0-1） were prepared. The structures of the catalysts were characterized using XRD, SEM, and TPR analyses. The catalytic activity of the catalysts for methane combustion was evaluated in a continuous flow microreactor. The results indicated that the active washcoats adhered well on the FeCrAl foils. The phases in the catalysts were Co--xMgxO solid solutions, α-Al2O3, and γ-Al2O3. The surface particle size of the catalysts varied with variations in the molar ratios of Co to Mg. The Co component of the Co1_xMgxO/Al2O3/FeCrAl catalysts played an important role in the catalytic activity for methane combustion. In the Co1-xMgxO/AluO3/FeCrAl series catalyst （x=0.2-0.8）, the catalytic activity in terms of x was in the order of 0.5〉0.2〉0.8 under the experimental conditions. The presence of Mg in these catalysts could promote the thermal stability to a large extent. There were strong interactions between the Co1-xMgxO oxides and the AluO3/FeCrAl supports.     

Fabrication of single‐walled carbon nanohorns incorporated a monolithic column for capillary electrochromatography

Single‐walled carbon nanohorns have received great interest for their unique properties and diverse potential applications. Herein, we demonstrated the feasibility of single‐walled carbon nanohorns incorporated poly(styrene‐divinylbenzene) monolith as the stationary phase for capillary electrochromatography, which were prepared by one‐step in situ copolymerization. Single‐walled carbon nanohorns were dispersed in styrene to give a stable and homogeneous suspension. The monolithic column gave effective separation for a wide range of aromatic compounds, which was based on hydrophobicity and π–π electrostatic stacking of single‐walled carbon nanohorns. The precisions of migration time and peak area varied in the ranges of 1.4–1.9% for intraday trials and 1.7–3.5% for interday trials, and 3.2–6.7% for intraday trials and 4.1–7.4% for interday trials, and 3.6–7.2% for inter‐column trials and 5.2–21.3% for inter‐column trials, respectively, indicating the good reproducibility of single‐walled carbon nanohorns embedded monolithic columns.