Team:SSHS-Shenzhen/Human Practices/13 Title


Mission: Internship of leaning to detect vegetables’ pesticide residue at the Food Inspection Center of Shenzhen

Date: August 3, 2018
Location: Food Inspection Center of Shenzhen

In order to survey the problems, existent or potential, of pesticide residue on the market, 5 members from our SSHS-Shenzhen team bought several kinds of common vegetables (Choy sum and Pakchoi) from the supermarket to the Food Inspection Center of Shenzhen. With the help of officers, we learned to accurately detect the pesticide residue and even conducted our own experiments.

During the experiment, we firstly sampled the vegetables we bought and turned them into a semi-solid mixture. After that, we took samples from the mixture and started the distill phase, by combining the mixture with ethyl solution and distilling evenly. Then we put it in the fridge with a temperature of -30 Celsius for 5 minutes. After that, we put the mixture into the centrifugal machine to divide them into three layers: a layer of vegetable juice, a layer of water and a layer of ethyl. Then we used the PSA (to pure) and centrifugate for a second time, and finally use the Gas Chromatography-Tandem Mass Spectrometry to inspect the results.

After analyzing the data, we found out that the Pakchoi contains three types of pesticide residue which are fliorosilazole 0.057mg/kg, worm nitrile 0.124mg/kg and cypermethrin 0.188mg/kg.

According to scientific information, those pesticide residues can induce not only cancer but can also hurt your skin. In conclusion, we found that the pesticides are deleterious to humans. This statement formed a concept that links up the processes towards further investigations.