Validation of short run time GC-EI (+) MS/MS method for pesticide residues determination in dry Hibiscus syriacus L. via application of d-MRM and end-point backflush quantification techniques

ABSTRACT

In this paper, the short injection method using GC-EI (+) MS/MS with end-point back-flush and dynamic-multi-reaction mechanism technique was validated for simultaneous determination of pesticide residues in dry Hibiscus syriacus L. applying QuEChERS extraction covering 176 GC-amenable pesticide residues. The GC optimum temperature program achieved a short run time and it was 20 minutes. The linearity of method was evaluated using matrix matched calibration standards at five concentration levels and the results showed that the coefficient of determination (r2) of each analyte was more than 0.990. The LODs was considered to be the lowest concentration that could be detected under optimal experimental conditions and it was 2 μg/kg (S/N = 3) and the LOQs was 10 μg/kg (S/N = 10). Acceptable recoveries of all the selected pesticides at three fortification levels were in the range from 60% to 102% with relative standard deviations ≤20% (n = 6) and matrix effect ranged from −31% to 6%‎. The method expanded measurement uncertainty was estimated as 40% (coverage factor k = 2, confidence level 95%). The validation results prove that it fit the intended use in accordance with the EC guidelines (SANTE/12682/2019) and could successfully expand the detection efficiency of pesticide residues in dry Hibiscus syriacus L. and other dry commodities.

KEYWORDS:

• Dry Hibiscus syriacus L.
• GC-MS/MS
• pesticide residues
• d-MRM
• QuEChERS
• backflush

Acknowledgments

We gratefully acknowledge the use of the facilities, equipment, and resources of the Central Laboratory of Residue Analysis of Pesticides and Heavy Metals in Foods (QCAP) during the period of the development of this paper.

Authorship contribution statement

Ahmed H. Hamzawy Conceptualization, Methodology, Software, Formal analysis, Investigation, Resources, Writing - original draft. Osama E. Hussien Writing - review & editing.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could appear to influence the work reported in this paper.

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Supplementary material

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