The Development Of Wide-bore Electrophoresis Automation Control System And High-power Ultrasonic Instruments

Compared to traditional capillary electrophoresis (CE), wide-boreelectrophoresis (WBE) with the inner cooling mechanism is under extensive researchbecause of its sample loading capacity. This paper aims to improve WBE from thetwo aspects as follows: control and sampling of the basic parameters such as the valueof vortage and current of high-voltage power supply (HVPS); conductivity detectionof buffer solution.Based on the ARM7-core microprocessor LPC2146, WBE automatic controlsystem was developed via the USB bus communication. The output voltage of HVPScan be adjusted in Windows application program. Besides, the system samples theoutput voltage and current of HVPS, and diplays the above two parameters in theapplication program. For further study on inner cooling effect, the system alsosamples and displays the import and export cooling fluid temperature of WBE.Power ultrasound has been widely used in new materials development andnatural medicine extraction field. However, the shortcomings such as low power andunadjustable frequency had limited its further applications. New ultrasonic powerdeveloped by our laboratory has realized high power and adjustable output frequencyby an external knob. Two control circuits based on analog component and singlechiphave been achieved. The driver modules used in the ultrasonic power have highfrequency isolation transformer to improve the reliability of the system. Differentsolvents and natural medicines need to adjust the ultrasound frequency, excitationmode and power to obtain the optimum ultrasound treatment parameters. Newexperimental platform consists of the ultrasonic power and container is built up forfurther study on application of power ultrasound in pharmaceutical chemistry andpharmaceutical analysis.In the production of ultrasonic transducers, admittance meter or impedanceanalyzer is used to screen a series of piezoelectric ceramic tube with a goodconsistency. Currently, there are three instruments to deal with the screen work, butthey all have shortcomings more or less. At low frequencies, the analog admittancemeter has bad performance of measurement accuracy. The admittance meter based onthe acquisition card is limited by its sampling frequency, so its measuring frequencyrange is relatively narrow. Agilent4294A impedance analyzer is expensive. To solve the above problem, we developed digital admittance meter system based on LPC2146.By using the USB bus communication, real-time control and display of the admittancecircle sampling results in Windows application program is realized.Meanwhile, the digital admittance meter can be also applied to measureconductivity of buffer solution in WBE system, which is a non-contact measurementmethod. The measurement process does not change the electrical and chemicalcharacteristics of buffer solution. After achieving continuous measurement, therelationship of buffer solution conductivity changing with the time in the differentposition can be provided to study on the characteristics of buffer solution in WBEsystem and new measurement method.