Removal of ten pesticide residues on/in kumquat by washing with alkaline electrolysed water

As a citrus fruit with edible peel, it is necessary to control the pesticide residues on/in kumquats to lower levels in order to avoid direct intake. This study aimed to investigate the removal of typical pesticide residues in kumquat by alkaline electrolysed water solutions. Field incurred samples and that from laboratory swap method were compared with an established procedure. The pesticide removal rates were similar when using field samples with incurred residues and that by swap method in lab. The removal effects of electrolysed water at pH = 11.0 and pH = 12.5 on ten pesticides were studied with swap method and compared with that of tap water. Samples containing the pesticide residues were extracted and cleaned up with QuEChERS method, followed by determination using GC-MS/MS and LC-MS/MS. The analytical results showed that the removal effect of electrolysed water on the studied pesticides depended on the pH value and washing duration. Compared with other washing solutions, the pH 12.5 electrolytic water was the most effective media for pesticide residue removal. Moreover, a washing duration of 20 min was optimum. In conclusion, alkaline electrolysed waterin higher pH provides as a potential removal strategy for pesticide residues on fruit surfaces.

Automated summary

Kumquats, a citrus fruit with edible peel, may have pesticide residues that need to be controlled. This study found that alkaline electrolysed water, especially pH 12.5, can effectively remove pesticide residues from the surface of kumquats. A washing duration of 20 minutes yielded the best results.