期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
离奇的Sybase数据库崩溃经历
1
作者 瞿松平 《网管员世界》 2008年第6期69-69,共1页
2006年在进行数据库清理优化时,我遇到了一个当时无法找到合理解释的问题。
关键词 SYBASE数据库 崩溃现象 清理优化 索引 数据空间
下载PDF
Optimization of Ultrasonic Extraction and Clean-up Protocol for the Determination of Polycyclic Aromatic Hydrocarbons in Marine Sediments by High-performance Liquid Chroma-tography Coupled with Fluorescence Detection 被引量:1
2
作者 PENG Xuewei YAN Guofang +3 位作者 LI Xianguo GUO Xinyun ZHOU Xiao WANG Yan 《Journal of Ocean University of China》 SCIE CAS 2012年第3期331-338,共8页
The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. Samples were ultrasonically extracted, and the extracts were pu... The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. Samples were ultrasonically extracted, and the extracts were purified with a miniaturized silica gel chromatographic column and analyzed with high performance liquid chromatography (HPLC) with a fluorescence detector. Ultrasonication with methanol-dichloromethane (2:1, v/v) mixture gave higher extraction efficiency than that with dichloromethane. Among the three elution solvents used in clean-up step, dichloromethane-hexane (2:3, v/v) mixture was the most satisfactory. Under the optimized conditions, the recoveries in the range of 54.82% to 94.70% with RSDs of 3.02% to 23.22% for a spiked blank, and in the range of 61.20% to 127.08% with RSDs of 7.61% to 26.93% for a spiked matrix, were obtained for the 15 PAHs studied, while the recoveries for a NIST standard reference SRM 1941b were in the range of 50.79% to 83.78% with RSDs of 5.24% to 21.38%. The detection limits were between 0.75 ng L-1 and 10.99 ng L-1for different PAHs. A sample from the Jiaozhou Bay area was examined to test the established methods. 展开更多
关键词 ultrasonic extraction marine sediment polycyclic aromatic hydrocarbon high performance liquid chromatography
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部