| Objective This study made models of pesticide residues in different vegetables,selected common cleaning methods in daily life to clean them,compared and analyzed the removal effects of different cleaning methods on organophosphorus pesticide residues in vegetables,and provided reference basis for people to wash vegetables before eating.Methods 1.Preparation of pesticide residue model:four kinds of pesticides were prepared into solutions in the proportion of 1:1000,vegetables were soaked in the above solutions for 20 minutes,picked up and drained,then packed in a plastic bag and refrigerated at 4℃ for 24 hours.2.Cleaning methods:easy cleaning methods commonly used in daily life were selected,including:clean water,salt water,NaHCO3 solution,special detergent for fruits and vegetables,and ultrasonic cleaning method.Different methods were used to clean the model of pesticide residues.3.Detection and analysis methods:the sample was pre-processed according to the national standard,the sample was detected by FPD detector using gas chromatography,and the residue was determined by comparing the standard substance.The experimental results were analyzed by one-way analysis of variance and multi-factor analysis using SPSS software.4.Analysis indicators:the influence of cleaning time on the results was considered in the clear water group and the special vegetable and vegetable detergent group;The effects of time and concentration on the results were considered in the salt water washing group and the NaHCO3 solution washing group.The influence of ultrasonic power on the results was considered in the ultrasonic cleaning group.Results 1.The average removal rate of residual pesticides in clean water was 46.76%.The cleaning time had a statistically significant difference on the removal rate of residual pesticides(P<0.05).The cleaning effect was the best after 10 minutes of cleaning.The highest removal rate of omethoate pesticides in leafy vegetables was 63.80%.2.The average removal rate of residual pesticides in brine washing is 52.72%.The difference between the cleaning time of saline solution and the concentration on the removal rate of residual pesticides was statistically significant(P<0.05).The highest removal rate of phorate pesticides remaining in root vegetables was 73.33%.3.The average removal rate of residual pesticides by NaHCO3 solution cleaning was 69.08%.The interaction between the cleaning time and concentration of NaHCO3 solution had a statistically significant difference in the removal rate of residual pesticides(P<0.05),and the highest removal rate of omethoate pesticides remaining in leafy vegetables was 90.93%.4.The average removal rate of residual pesticides by ultrasonic cleaning is 80.25%.The difference of ultrasonic power on the removal rate of residual pesticides was statistically significant(P<0.05),and the highest removal rate of pesticides of omethoate remaining in leafy vegetables was 96.70%.5.The average removal rate of residual pesticides by special fruit and vegetable detergents is 87.92%.The soaking time of special fruit and vegetable detergents was statistically significant(P<0.05).The removal rate of phorate pesticides remaining in eggplant vegetables was 98.43%.The results showed that the special fruit and vegetable detergent cleaning and ultrasonic cleaning had better removal effect on pesticide residues in vegetables.Conclusion Cleaning with water and saline solution is generally effective in removing residual pesticides.NaHCO3 solution cleaning,ultrasonic cleaning and fruit and vegetable detergents have a good effect on pesticide removal rate,but the residual conditions after detergent cleaning are unknown.Cleaning time and solvent concentration have an effect on the removal rate.In daily life,you can use NaHCO3 solution or ultrasound to clean vegetables.The cleaning time should not be too long,and the concentration of other solvent solutions should not be too high. |
