Determination of four sulfonylurea herbicides in tea by matrix solid‐phase dispersion cleanup followed by dispersive liquid–liquid microextraction

Abstract

Matrix solid-phase dispersion combined with dispersive liquid-liquid microextraction has been developed as a new sample pretreatment method for the determination of four sulfonylurea herbicides (chlorsulfuron, bensulfuron-methyl, chlorimuron-ethyl, and pyrazosulfuron) in tea by high-performance liquid chromatography with diode array detection. The extraction and cleanup by matrix solid-phase dispersion was carried out by using CN-silica as dispersant and carbon nanotubes as cleanup sorbent eluted with acidified dichloromethane. The eluent of matrix solid-phase dispersion was evaporated and redissolved in 0.5 mL methanol, and used as the dispersive solvent of the following dispersive liquid-liquid microextraction procedure for further purification and enrichment of the target analytes before high-performance liquid chromatography analysis. Under the optimum conditions, the method yielded a linear calibration curve in the concentration range from 5.0 to 10 000 ng/g for target analytes with a correlation coefficients (r(2)) ranging from 0.9959 to 0.9998. The limits of detection for the analytes were in the range of 1.31-2.81 ng/g. Recoveries of the four sulfonylurea herbicides at two fortification levels were between 72.8 and 110.6% with relative standard deviations lower than 6.95%. The method was successfully applied to the analysis of four sulfonylurea herbicides in several tea samples.

Preparation of iron‐based MIL‐101 functionalized polydopamine@Fe3O4 magnetic composites for extracting sulfonylurea herbicides from environmental water and vegetable samples

“…The performances of this method and previously published methods [28][29][30][31][32] for determining SUHs are shown in Supporting Information Table S4. The method gave satisfactory recoveries and similar or lower LODs and RSDs to the other methods.…”

Determination of Haloxyfop-Methyl, Linuron, and Procymidone Pesticides in Carrot Using SLE-LTP Extraction and GC-MS

“…The extraction techniques used for pesticide residue analysis in plant products include dispersive solid-phase extraction (dispersive-SPE) (Anastassiades et al 2003); QuEChERS (quick, easy, cheap, effective, robust, and safe) (Lehotay et al 2010a); supercritical fluid extraction (SFE) (Shizuka et al 2014); microwave-assisted extraction (MAE) (Karmakar et al 2012); matrix solid-phase dispersion (MSPD) (Liang et al 2014); solid-phase extraction (SPE) (Sanagi et al 2013); pressurized liquid extraction (PLE) (Celeiro et al 2014); solid-phase microextraction (SPME) (Dias et al 2015); and stir bar sorptive extraction (SBSE) (Giordano et al 2011).…”

Dispersive Solid–Liquid Extraction Coupled with LC-MS/MS for the Determination of Sulfonylurea Herbicides in Strawberries

“…Unfortunately, the original QuEChERS method provided relatively weak recovery values (<70%) for sulfonylurea herbicides [7,8]. To overcome this issue, several sample preparation techniques, including solid phase extraction (SPE) using Chem Elut SPE cartridges [9] or a mini-column packed with oxidized carbon nanotubes [10], magnetic-SPE using multiwalled carbon nanotubes [11], dispersive SPE (d-SPE) using C 18 and graphitized carbon black (GCB) [12], dispersive liquid–liquid microextraction (DLLME) [13], matrix solid phase dispersion followed by DLLME [14], and stir bar sorption extraction [15], have been studied and validated. Lee et al [8] reported that a modified QuEChERS method involving C 18 cleanup after extraction with a citrate buffer provided the best recoveries for some sulfonylurea herbicides in brown rice and rice straw.…”