A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrumen...A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.展开更多
A simplified probabilistic analysis of geomembrane punctures from granular material was presented when subjected to liquid pressure.The probability distribution of contact force between geomembrane and granular materi...A simplified probabilistic analysis of geomembrane punctures from granular material was presented when subjected to liquid pressure.The probability distribution of contact force between geomembrane and granular material was obtained based on the principle of equal probability and assumptions that grains are spheres with constant size.A particle flow code PFC3Dwas employed to simulate the contact process which indicates a good agreement with the theoretical probabilistic analysis.The odds of geomembrane puncture from grains of constant size were obtained by evaluating the puncture force which should not exceed the puncture resistance of geomembrane.The effects of grain radius,grain rigidity and liquid pressure were studied in more detail and displayed in graphs.Both high-level of liquid pressure and large grain can result in high risk of geomembrane puncture.The influence of grain rigidity on the geomembrane puncture odds is significant.For granular material with a grain size distribution,the geomembrane puncture odds can be estimated by the grain size distribution,served as weight function and it is a cautious design if the largest grain is chosen as the design grain size.展开更多
基金Project(51178321)supported by the National Natural Science Foundation of ChinaProject(2012ZX07403-001)supported by the National Science and Technology Major Project,ChinaProject(20120072110050)supported by the Research Fund for the Doctoral Program of Higher Education of China
文摘A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.
基金Project(51079047)supported by the National Natural Science Foundation of China
文摘A simplified probabilistic analysis of geomembrane punctures from granular material was presented when subjected to liquid pressure.The probability distribution of contact force between geomembrane and granular material was obtained based on the principle of equal probability and assumptions that grains are spheres with constant size.A particle flow code PFC3Dwas employed to simulate the contact process which indicates a good agreement with the theoretical probabilistic analysis.The odds of geomembrane puncture from grains of constant size were obtained by evaluating the puncture force which should not exceed the puncture resistance of geomembrane.The effects of grain radius,grain rigidity and liquid pressure were studied in more detail and displayed in graphs.Both high-level of liquid pressure and large grain can result in high risk of geomembrane puncture.The influence of grain rigidity on the geomembrane puncture odds is significant.For granular material with a grain size distribution,the geomembrane puncture odds can be estimated by the grain size distribution,served as weight function and it is a cautious design if the largest grain is chosen as the design grain size.
