Extraction of imide fungicides in water and juice samples using magnetic graphene nanoparticles as adsorbent followed by their determination with gas chromatography and electron capture detection.

In this paper, a sensitive analytical method for four fungicides (procymidone, folpet, vinclozolin and ditalimfos) in environmental water and juice samples was developed by using magnetic solid-phase extraction (MSPE) with magnetic graphene nanocomposite (G-Fe3O4) as the adsorbent, followed by determination with gas chromatography and electron capture detection. Parameters such as the amount of G-Fe3O4, extraction time, ionic strength and pH of the sample solution, desorption solvent and desorption time were optimized. Under the optimum conditions, the enrichment factors of the method for the analytes were in the range from 1495 to 1849. The limits of detection for the fungicides ranged from 1.0 to 7.0 ng L(-1). The recoveries of the method for the analytes were in the range from 79.2 to 102.4%. The developed G-Fe3O4-MSPE method was simple and efficient for the extraction and determination of the four fungicides in water and grape juice samples.