Suitability of PSA (Primary Secondary Amines) and Z-Sep as clean-up sorbents in AOAC official method 2007.01 for analysis of trifloxystrobin and CGA 321113 residue in dragon fruit, star fruit and watermelon

N., Chai Keong; Siti Hajar H.; Khairatul A. M.

Suitability of PSA (Primary Secondary Amines) and Z-Sep as clean-up sorbents in AOAC official method 2007.01 for analysis of trifloxystrobin and CGA 321113 residue in dragon fruit, star fruit and watermelon

2020

N., Chai Keong | Siti Hajar H. | Khairatul A. M.

Two types of clean-up sorbents, namely PSA (Primary Secondary Amines) and Z-Sep were tested for reliability in AOAC official method 2007.01 for generating accurate results for analysis of trifloxystrobin and CGA 321113 (trifloxystrobinmetabolite) in dragon fruit, star fruit and watermelon. A known amount of both analytes was fortified onto separate analytical portions of dragon fruit, star fruit and watermelon respectively, followed by an extraction clean-up procedure using either PSA or Z-Sep. The extracts were analysed by Liquid Chromatography Tandem Mass Spectrometry (LCMS-MS) analysis. Measured concentrations were compared with a theoretical fortified value in order to determine its recovery. Results indicated that both PSA and Z-Sep generated acceptable recovery of trifloxystrobin ranging from 76.8 – 107.7%. However, when PSA alone was used as the clean-up material, significant loss of CGA 321113 was deduced from low average recovery values in dragon fruit (47.1%), star fruit (57.4%) and watermelon (31.7%) for fortification level of 0.01 mg/kg. For higher fortification level of 0.1 mg/kg, lower average recovery values of CGA 321113 were reported in dragon fruit (23.9%), star fruit (15.4%) and watermelon (14.6%). In all the studied fruits, Z-Sep showed recoveries of CGA 321113 within the range of 80.4– 124.2% at 0.01 and 0.1 mg/kg fortification levels indicating no significant loss during the clean-up procedure. Based on two types of residue definitions (MRL compliance and dietary risk assessment), it can be concluded that for analysis of CGA 321113, Z-Sep should be used as the clean-up sorbent in the clean-up procedure.

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