ADELA MEGHESAN – BREJA, CONSTANTIN MARUTOIU, CLAUDIA CIMPOIU MULTI-RESIDUES ANALYSIS FOR 88 PESTICIDES AND METABOLITES FROM SOIL BY GAS CHROMATOGRAPHY-TIME - OF - FLIGHT MASS SPECTROMETRY
An easy and fast Gas Chromatography-time-of-Flight Mass Spectrometry (GC-TOF-MS) method for 88 pesticides and metabolites identification and quantitation from soil was developed. Most widely used pesticides from group of pesticides, like herbicide, insecticide, fungicide were analyzed. The soil samples were extracted with acetonitrile acidified with 1% acetic acid; then extract was buffered with anhydrous magnesium sulfate and sodium acetate and then was cleaned-up by solid-phase extraction (SPE) with anhydrous magnesium sulfate and primary-secondary amine (PSA) . The final extract was directly injected in GC. Analysis of extracts was carried out by GC-TOF-MS within 29.2min run time. The GC method was validated for soil in term of linearity, accuracy, limit of detection (LOD) and limit of quantification (LOQ). Good linearity with correlation coefficients (r2) higher than 0.98 was obtained. For 60 analytes recoveries were in range of 70-120% and LOQ values in range of 0.01- 0.05mg/kg. Instrument LOD values generally varied from 0.5 to 0.8ng . mL-1. The developed method was successfully tested on five soil samples from different cultivated lands, with and without known history in terms of pesticide use.
Keywords: Soil; Pesticide residues; Multi-residues analysis; Gas chromatography–Time-of-flight Mass Spectrometry, Solid-phase extraction