ABSTRACT
An enhance matrix removal ( EMR) QuEChERS method for simultaneous determination of 22 triazine herbicide residuals such as atrazine, propazine, terbumeton, and desmetryn in corn was established and validated. The corn samples were initially extracted with acetonitrile ( MeCN ) in high-speed homogenization, and the targeted pesticides were prepared using EMR-Lipid (Enhanced matrix removal-lipid) method to clean-up and EMR-Polish to salt out, separated on a Kinetex XB-C18 with acetonitrile and 0. 1%formic acid aqueous as eluant, and then detected by UFLC-MS / MS under positive ( ESI+ ) electrospray ionization and MRM models. The average recoveries of 22 herbicides were in the range of 72% -105% at the spiked level of 5, 10 and 20 μg / kg. The relative standard deviations were less than 15% . In the method validation, correlation coefficients were higher than 0. 993 with the linear range from 1. 0 μg / L to 50 μg / L. The qualitative analysis and quantitative analysis were investigated by UFLC-MS / MS and matrix-matched calibration curves. The results showed that EMR QuEChERS combined with UFLC-MS / MS purification method was rapid, accurate and sensitive for the determination of 22 triazine herbicides residues in corn.
ABSTRACT
A high performance liquid chromatography-tandem mass spectrometric method ( HPLC-MS/MS ) was developed for the simultaneous determination of 31 kinds of triazine herbicides in farmland soils. Samples were extracted by accelerated solvent extraction ( ASE ) and purified by Oasis MCX solid phase extraction ( SPE) cartridges, and then analyzed by HPLC-MS/MS in multiple reaction monitoring ( MRM) mode with positive electrospray ionization. The analytical column was Phenomenex Luna C18 ( 150 mm í 2. 0 mm í3 μm) and the mobile phases were acetonitrile and water containing 0. 1% (V/V) formic acid. The limits of detection (S/N≥3) were 0. 008-0. 440 μg/L. All of the triazine herbicides had good linear responses with r≥0 . 996 and the average recoveries in the spiked levels of 0 . 40-40 . 0 μg/kg ranged from 76 . 9%-102 . 0%with the RSDs of 3 . 4%-10 . 3%. The HPLC-MS/MS method had been applied for the detection of the triazine herbicide residues in farmland soils from Shenyang region and the results showed that atrazine, simazine, prometryne and atrazine-desethyl were the main triazine herbicides in the region.