本研究以建立保健食品中有机氯农药残留量的测定为目的。样品经石油醚提取,浓缩、酸化后,以弹性石英毛细管柱DB-1701(30 m×0.32mm×0.25μm),63Ni-ECD电子捕获检测器,以及六六六(BHC)、滴滴涕(DDT)及其同分异构体有机氯农药为...本研究以建立保健食品中有机氯农药残留量的测定为目的。样品经石油醚提取,浓缩、酸化后,以弹性石英毛细管柱DB-1701(30 m×0.32mm×0.25μm),63Ni-ECD电子捕获检测器,以及六六六(BHC)、滴滴涕(DDT)及其同分异构体有机氯农药为对照品,配制成正己烷溶液,进样口温度:230℃;检测器温度:300℃;分流比:1/10;柱流量:1.00 m L/min;程序升温:初始100℃,每分钟10℃升至220℃,再每分钟8℃升至250℃,展开更多
Gas holdup is one of the key parameters in flotation process. Gas holdup as measured by a differential pressure method was investigated and the relative errors compared to the average gas holdup from the volume expans...Gas holdup is one of the key parameters in flotation process. Gas holdup as measured by a differential pressure method was investigated and the relative errors compared to the average gas holdup from the volume expansion method. The errors were used to establish optimum measurement positions. The results show that the measurement position should be in the middle of the column and in the region half way from the center to the wall (the half-radius). The gas holdup along the axial direction is lower at the bottom and higher at the top of the floatation column. The gas holdup along the radial direction is lower near the wall and higher near the center of the flotation column. The average gas holdup measure- ment can be replaced by regional gas holdup values.展开更多
文摘本研究以建立保健食品中有机氯农药残留量的测定为目的。样品经石油醚提取,浓缩、酸化后,以弹性石英毛细管柱DB-1701(30 m×0.32mm×0.25μm),63Ni-ECD电子捕获检测器,以及六六六(BHC)、滴滴涕(DDT)及其同分异构体有机氯农药为对照品,配制成正己烷溶液,进样口温度:230℃;检测器温度:300℃;分流比:1/10;柱流量:1.00 m L/min;程序升温:初始100℃,每分钟10℃升至220℃,再每分钟8℃升至250℃,
基金supports for this work provided by the NationalKey Technology R&D Program in the 11th Five-Year Plan of China(No. 2008BAB31B03)
文摘Gas holdup is one of the key parameters in flotation process. Gas holdup as measured by a differential pressure method was investigated and the relative errors compared to the average gas holdup from the volume expansion method. The errors were used to establish optimum measurement positions. The results show that the measurement position should be in the middle of the column and in the region half way from the center to the wall (the half-radius). The gas holdup along the axial direction is lower at the bottom and higher at the top of the floatation column. The gas holdup along the radial direction is lower near the wall and higher near the center of the flotation column. The average gas holdup measure- ment can be replaced by regional gas holdup values.
