Construction Of Rapid Detection System Of Heavy Metals And Application On Safety Assessment

At present,the serious problem of heavy metal pollution in our country has caused a huge impact on the social development and economic construction.According to the statistics,there are about 12 million tons of grains contaminated by heavy metals in our country each year,resulting in over 200 billion yuan of economic losses,and the total economic losses caused by occupational diseases and industrial accidents exceeds 300 billion yuan in each year.In such situation,it makes us focus on the problem of heavy metal pollution.Heavy metal detection plays a crucial role on the management of heavy metal pollution.Now,there are two limitations in China’s detection of heavy metals: The first limitation is the dissolving with mixed acid to solid samples such as soil or air.Disadvantages of this approach is the long cycle of dissolving and the process is more cumbersome.What’s more,it will produce harmful substances making laboratory staff get damage while processing samples;The second limitation is the existence of shortcomings of heavy metal detection methods.Using ICP-MS detection of heavy metals,its advantages are high sensitivity,good accuracy,fast analysis and multi-element simultaneous detection.However,the high cost of instrumentation and strict requirements about temperature and humidity of the testing environment become a burden to customers.The XRF method can directly analyze finished products,but it detects heavy metal elements with a lower testing line and repeatability.For AAS,the equipment is easy to operate.It has high accuracy and wide range of analysis,which is not suitable for on-site testing.In order to solve the problems of the above detection equipment,this paper constructed a rapid detection system for heavy metals based on electrochemical principle and LabVIEW virtual instrument technology.It introduces the construction of heavy metal detection equipment and hardware and software components,including the host computer and lower computer of the software design,hardware measurement circuit and printed circuit PCB design and hardware modules.Functional hardware modules includes automatic mixing device,automatic dropping device and automatic cleaning device.The use of stepper motor control mixing system can ensure the stability of the solution stirring speed;Testing with a syringe pump for automatic drip,the injection error can achieve basically the accuracy of pipette guns and other high-precision laboratory instruments.In the various functional tests,the instrument is accuracy enough to make the testing requirements.Afterwards,the equipment was used to test the soil heavy metals in a certain area of Tianjin,and the ecological health evaluation was carried out based on testing results.Although this product can not be industrially produced temporarily,it provides ideas for remedying defects in heavy metals detection with the high sensitivity,good accuracy and low cost are applicable to a wide range of trace detection equipment in the production and living environment.