A reliable and accurate liquid chromatography with evaporative light scattering detection (LC-ELSD) method was developed for simultaneous determination of five constituents in Xue-Fu-Zhu-Yu capsule, a widely used prescription of traditional Chinese medicine (TCM). The chromatographic separation was performed on a Symmetry C 18 column (150 mmÂ4.6 mm, 5.0 μm) using gradient elution of acetonitrile and water (containing 1.0% acetic acid). The flow rate was 0.6 mL/min and the temperature of column was 30°C. A good linearity correlation was obtained over the investigated concentration ranges. Recoveries of the five components varied from 97.31% to 99.84% (RSD < 4.0%). The validated method was successfully applied to the quality assessment of Xue-FuZhu-Yu capsule.
In this work, we present a microfluidic platform which is capable of carrying out a series of laboratorial operations on a disposable chip. The platform employs coil arrays to transport biological samples attached on magnetic beads through different reaction zones in aqueous solutions. Micromachined thermopneumatic valves are adopted as the interfaces between sequential reactions. The self-contained system is composed of a disposable microfluidic reaction (MFR) chip and a fluidic driving/sensing (FDS) module. Various reaction zones with different functionalities are implemented on the MFR chip. Arrays of coils and micromachined heater/sensing chips are integrated into the FDS module. Also, novel indirect-heating thermo-pneumatic valves (IH-TPVs), which are monolithically integrated into the disposable MFR chip, are proposed and characterized. With an applied voltage of 3.2 V, the IH-TPV effectively isolates two adjacent reaction zones, while its temperature elevation is sufficiently low for biological samples and reagents. By employing the proposed approach, we design and implement a miniaturized biochip system which carries out the processes of DNA extraction, purification and amplification from whole blood sample. The dimension of the fully-integrated system is 72 mm×54 mm×11 mm, and the system could be fully operated with a 12 V DC power supply. DNA extraction and purification from human whole blood followed by PCR amplification for the 122 bp segment is successfully performed by using the system.
To determine the lower limit of the pore size of saturated kerosene indirectly for testing porosity, the combined total porosity was first calculated using carbon dioxide adsorption, nitrogen adsorption, and mercury intrusion tests. Then the combined porosity is gradually accumulated from large pores to tiny pores. When the accumulation is equal to the total kerosene porosity, the corresponding pore diameter is a minor pore diameter measured by kerosene porosity. A total of 5 samples were collected this time. The lower limit of kerosene porosity was determined as 3.1nm, which shows that the kerosene saturation method can describe most of the shale’s mesopores and macropores. This method can also be extended to determine the lower limit of the pore size by the porosity method, such as helium.
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