Micro-solid-phase extraction (µ-SPE) of organophosphorous pesticides from wheat followed by LC-MS/MS determination

ABSTRACT

A rapid, selective and effective method of extraction, clean-up and concentration of organophosphorous pesticides from wheat followed by electrospray (ESI) LC-MS/MS analysis was developed. The μ-SPE (micro-solid-phase extraction) procedure resulted in good analytical performance and reduced at the same time matrix effects, analysis time and solvent consumption. Limits of detection (LODs) and quantification (LOQs) were in the range of 0.3–10 and 1–30 μg kg⁻¹, respectively, with good reproducibility (RSD ≤ 13.8) and recoveries between 75% and 109%. Coefficients of determination (r²) were greater than 0.996 for the studied pesticides. Despite the reduced sorbent bed mass of μ-SPE tips (4.2 mg), the analytical data showed that no saturation phenomena occurs in the tested range of concentration both for single compounds and mixtures. Several real samples were analysed and the concentrations of the selected pesticides were found to be below the respective maximum residue limit (MRLs).

KEYWORDS:

• Organophosphrous pesticides
• micro-solid-phase extraction (µ-SPE)
• LC-MS/MS
• wheat

ORCID

Camilla Montesano http://orcid.org/0000-0001-7721-4961

Dario Compagnone http://orcid.org/0000-0001-7849-8943

Additional information

Funding

The financial contribution of the Fondazione Tercas, under the Progetti di Eccellenza scheme, is acknowledged; as well as that of the Italian Ministry of Foreign Affairs for the Project ‘Materiali nanostrutturati per sistemi (bio)chimici sensibili ai pesticidi’.