Validation and global uncertainty of a gas chromatographic with mass spectrometry method for fenamidone analysis in grapes and wines

Abstract

Fenamidone is an imidazolinone fungicide recently introduced in viticulture practices. This work reports the validation and assessment of global uncertainty of a gas chromatographic with mass spectrometry method to analyze fenamidone in grapes and wines. This method consists in a simple and fast liquid-liquid extraction step followed by chromatographic determination. Limits of detection for fenamidone in grapes and wines were, respectively, 0.05 mg/kg and 0.06 mg/L, precision was below 9.4% and average recovery was 89 ± 5%. In the concentration range from 0.05 to 1.00 mg/kg (or mg/L) of fenamidone, global uncertainty calculated following the EURACHEM/CITAC rules, and also by the Horwitz function, was below 25%. The EURACHEM/CITAC global uncertainty budget used gave lower estimates than those obtained from the Horwitz function.

Keywords:

• Fenamidone residues
• Fungicide
• Grapes
• Wines
• Gas chromatography with mass spectrometry
• Method validation
• Global uncertainty

Acknowledgement

The authors wish to thank the FCT–Fundação para a Ciência e Tecnologia, in Pōrtugal, for financial support (SFRH/BD/4648/2001).

Notes

∗(expressed as % relative standard deviation), determined for concentrations of 0.50, 0.10, 0.20, 0.50 and 1.00 mg/L of fenamidone, respecting to standards preparation (U₁), calibration curve (U₂), precision (U₃) and accuracy (U₄).