Behaviour of spirotetramat residues and its four metabolites in citrus marmalade during home processing

ABSTRACT

The effect of home processing on the residues of spirotetramat and its four metabolites (B-enol, B-glu, B-mono and B-keto) in citrus marmalade is comprehensively investigated in this paper by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). A five-fold recommended dose of spirotetramat was applied to citrus fruit under field conditions and the processing included five steps: washing, peeling, pre-treatment for peel, mixing and boiling. The results showed that spirotetramat was the predominant component detected in unprocessed citrus, accounting for 64%. All the detected residues were primarily deposited on citrus peel, except for B-enol which was also present in the citrus pulp. Washing reduced spirotetramat, B-enol, B-glu and B-keto by 83%, 56%, 41% and 16%, respectively, and pre-treatment of the peel removed between 42% and 68% of the residues. Four compounds were all below the limit of detection after the mixing step. In the final product, only B-keto was detected at the concentration of 0.010 mg kg^–1. After the whole process, the processing factors for spirotetramat, B-enol, B-glu and B-keto were < 0.041, < 0.125, < 0.294 and 0.313, respectively, which indicated that home processing can significantly reduce residues of spirotetramat and its metabolites in citrus marmalade.

KEYWORDS:

• Citrus
• spirotetramat
• metabolites
• home processing
• LC-MS

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the China Agriculture Research System [grant number CARS-27], the National Risk Assessment Program for Agricultural Products Quality and Safety [grant number GJFP2015004], the National Key Technology R&D Program [grant numbers 2007BAD47B07 and 2009BADB7B04], and the Natural Science Foundation of Chongqing [grant number cstc2013jjB80009].