Multi-sample Unit Pretreatment Platform And Its Software Design

Sample pretreatment is a time-consuming and easy-to-introduce analytical measurement error step in the sample analysis process.With the development of laboratory automation technology,fully automated sample pretreatment operations that replace cumbersome manual processing have become the development trend of processing equipment in research fields such as food safety and biomedicine.At present,the sample preparation equipment has shortcomings such as single function,long time period,small sample processing volume and low degree of automation.To this end,based on the technical requirements of sample pretreatment,this paper designed a fully automatic sample pretreatment platform,and developed the platform's upper computer software.The main contents of this paper are as follows:First,the mechanical structure of the sample pretreatment platform is analyzed,and the working principle of the syringe and distribution valve during the pipetting process are analyzed.In order to eliminate cross-contamination between solvents and ensure the pipetting accuracy of the system,the workflow plan of the sample pretreatment platform is designed.The process includes five steps: automatic cleaning,rinsing,pipetting,cleaning and sonication.Second,the control scheme of the pipetting system,transmission positioning system and ultrasonic extraction device of the platform is designed.The upper and lower computer adopts the master-slave control mode,through RS-485 serial port communication mode for command transmission and signal feedback.The upper computer is responsible for processing experimental data,sending command instructions and monitoring the experimental status.The lower computer is responsible for driving the motor and continuously scanning the working status of the injection pump,so as to control the platform to automatically complete all functions.Third,the upper computer software system of the sample pretreatment platform is designed according to the software requirements.The functions of the software system are divided into several modules such as parameter setting,pre-processing scheme preparation,experimental state monitoring and communication.The human-computer interaction interface is designed for each functional module,and the various modules of sequential state machine experiment design,injection pump instruction generation algorithm and data processing and management are completed.Finally,the software system and the performance of platform is tested,and the factors affecting its performance is analyzed.The test results show that the software system has perfect functions,strong interface interaction and convenient operation.The sample preparation platform has multiple sample positions,and the absolute error of the pipetting system reaches ± 0.05 mL,which realizes solvent transfer and ultrasonic extraction processing,effectively solves the problem of high labor intensity in sample preparation,and further improves the detection Efficiency and accuracy of test results.