Design Of Gradient Elution System Based On Chromatography

Chromatographic Analysis is a very important method of modern separating and analyzing. Gradient elution system is an important sophisticated analyzing device for Chromatographic Analysis. It has comprehensive application in many fields such as oil industry, chemical industry, environmental protection, foodstuff procedure and so on. The development of gradient elution system is a complicated system engineering, involving mechanics, electronics, automation, computer, etc.Gradient elution system includes gradient system, collecting system, CCD detector and data processing system of computer. With the development of system, it can edit and save gradient file. At the same time, gradient mix precision is improving. The performance of computer and CCD detector is also improving quickly, data processing system will be perfected and display multi-wavelength atlas, which will improve the efficiency of chromatographic analysis.In this paper, the basic principle of gradient elution is introduced and mathematical model is established in the first place. The hardware based on basic principle of the system is designed. Then, the HMI is designed and the program of the system is written. Gradient mix precision is always a problem of gradient elution system, the system figures out a way to solve the problem by controlling the speed of the motor.At last, the computer software based on LabWindows/CVI is designed. The software can communicate with PLC and CCD detector. Then, software interface is designed and relevant program is written. Gradient file can be edited, saved, opened and loaded in the software interface. At the same time, the computer software obtains data from CCD detector applying multi-thread technique and display the absorbance atlas. By comparing the atlas of computer software interface, we can see that the application of gradient elution can shorten separation time and improve separation efficiency.