Analysis of pesticide residues in sugarcane juice using QuEChERS sample preparation and gas chromatography with electron capture detection

QuEChERS sample preparation was used for the determination of 7 pesticides residues in 80 samples of sugarcane juice collected from two Brazilian cities, in two different periods. The method involved extraction with acetonitrile, liquid–liquid partition with addition of MgSO4 and NaCl followed by dispersive SPE cleanup with PSA sorbent and the analyses were carried out with a GC–ECD equipment. The method was validated using sugarcane juice spiked at 0.025, 0.10 and 0.20 mg/L and the average recovery by the method varied from 62.9% to 107.5% with RSDs < 18%. The method showed good linearity and the LODs for the pesticides studied ranged from 0.003 to 0.04 mg/L. No pesticide residue was detected (>LOD) amongst the 80 samples analysed.