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141.
142.
M. W. F. Nielen J. De Jong R. W. Frei U. A.Th. Brinkman 《International journal of environmental analytical chemistry》2013,93(1-3):37-48
Abstract A strongly basic anion-exchange resin is used for the trace enrichment and automated sample handling of phenol, with subsequent determination by reversed-phase liquid chromatography with fluorescence detection. Because of the presence of high concentrations of ionic compounds in the water samples tested, phenol is first trapped on a relatively long precolumn filled with a highly hydrophobic packing material; during this step, (in) organic anions which are not retained, are flushed to waste. In the next step, phenol is desorbed from this column at high pH and sorbed in a small zone (“peak compression”) on a short precolumn containing the anion exchanger. In the analysis of tap and river water samples, the detection limit was found to be 10ppt (1:1011). 相似文献
143.
A selective and sensitive liquid chromatography tandem mass spectrometry method (LC‐MS/MS) was developed and validated for the determination of cefdinir in rat plasma and urine. Following a simple protein precipitation using methanol, chromatographic separation was achieved with a run time of 10 min using a Synergi 4 µ polar‐RP 80A column (150 × 2.0 mm, 4 µm) with a mobile phase consisting of 0.1% formic acid in water and methanol (65:35, v/v) at a flow rate of 0.2 mL/min. The protonated precursor and product ion transitions for cefdinir (m/z 396.1 → 227.2) and cefadroxil, an internal standard (m/z 364.2 → 208.0) were monitored in the multiple reaction monitoring in positive ion mode. The calibration curves for plasma and urine were linear over the concentration range 10–10,000 ng/mL. The lower limit of quantification was 10 ng/mL. All accuracy values were between 95.1 and 113.0% and the intra‐ and inter‐day precisions were <13.0% relative standard deviation. The stability under various conditions in rat plasma and urine was also found to be acceptable at three concentrations. The developed method was applied successfully to the pharmacokinetic study of cefdinir after oral and intravenous administration. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
144.
Soo Ouk Jang Hyun Jong You Young-Woo Kim Yong Ho Jung In Uk Hwang Jae Yang Park Heon Lee 《Plasma Chemistry and Plasma Processing》2014,34(1):229-237
To deposit copper seed layer on ultra large scale integration devices, a large-area (Ø 378 mm) electron cyclotron resonance plasma has been generated by using permanent magnets-embedded Lisitano antenna. The plasma source operates in the pressure range of 0.2–1.5 mTorr with microwave power range of 500–2,000 W. By using a Langmuir probe, the electron density and temperature have been measured near the DC sputter target position. Measurements indicate argon plasmas having electron densities of ~5 × 1010/cm and electron temperatures of 5 eV with 750 W microwave power at gas pressures of 0.5 mTorr. Using this plasma source and a DC sputter, we obtained excellent conformal copper seed layer with high aspect ratios of 12:1. This is in contrast with conventional methods using magnetron sputter, which has aspect ratios of 2–3:1. Also, improvements are observed in the smoothness (root mean square roughness of 1.345 nm), uniformity (2.5 % at 300 mm wafer), and sidewall symmetricity (more than 95 %) of the copper seed layer. 相似文献
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Jong Min Park Chang Young Jung Joong Hyun Cho Dae Hyun Kim Yue Wang Jae Yun Jaung 《Tetrahedron letters》2018,59(35):3322-3325
New quinoxaline-based organic sensitizer bearing di-anchoring group for dye-sensitized solar cells (DSSCs) was synthesized from diethyl 4,5-diaminophthaltate, in which was prepared under mild condition by using Takehito’s method. The synthesized sensitizer was compared with mono-anchoring sensitizer through absorption spectra, emission spectra, J-V curve, and IPCE spectra, indicating the di-anchoring group leads to a noticeable improvement of Jsc value owing to more efficient intramolecular charge transfer and channel number increment. 相似文献
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Park Hye Min Kim Jeong Ho Kim Young Seok Kang Sung Won Oh Dae Min Lee Un Jang Kim Do Hyung Joo Koan Sik 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(2):1051-1057
Journal of Radioanalytical and Nuclear Chemistry - An in situ detector for radiological assessments of strontium-90 (90Sr) in river and lake water is developed, based on a CaF2(Eu) scintillator,... 相似文献
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