Determination of Ten Sulfonyl Urea Herbicides in Unpolished Rice by Solid-phase Extraction Cleanup and LC-Diode Array Detection

Abstract

A liquid chromatographic (LC) method with diode array detection (DAD) was developed for screening of 10 sulfonyl urea herbicide residues in unpolished rice. The investigated herbicides were azimsulfuron, bensulfuron-methyl, chlorimuron-ethyl, chlorsulfuron, ethoxysulfuron, flazasulfuron, imazosulfuron, metsulfuron-methyl, pyrazosulfuron-ethyl and tribenuron-methyl. Acetonitrileῌwater (2 : 1) extracts of rice samples were cleaned up with solid-phase extraction cartridges (octadecylsilane-bonded silica (ODS) and graphitized carbon black (GCB)). Three fractions of the GCB eluate were taken for analysis using 3 separate injections in order to avoid interference in LC-DAD analysis and to reduce analyte coelution problems. Recoveries from rice samples fortified with the 10 herbicides at 0.05 and 0.2 mg/g ranged from 46.6 to 119.6ῌ, and coe$cients of variation were 3.1ῌ12.6ῌ. The quantitation limits were 0.01ῌ0.02 mg/g.

Residue analysis of orthosulfamuron herbicide in fatty rice using liquid chromatography–tandem mass spectrometry

“…Sulfonylurea herbicides have been traditionally extracted by liquid–liquid extraction (LLE) and solid-phase extraction (SPE); however, these extraction methods have undesirable features, such as time-consuming and multi-step procedures, and large consumption and discharge of organic solvents [8,10–12] . On the other hand, the use of the QuEChERS method has been effectively improving the demerits of traditional extraction methods because of its small scale LLE, dispersive SPE, and a combination with mass spectrometry [13,15] .…”

“…High-performance liquid chromatography (HPLC) with an UV or diode array, mass spectrometry (MS) or tandem mass spectrometry (MS/MS) detection system was the most common approach for the determination of SUs in grains because of their polar characteristic, low volatility, and thermal instability [8,10–12] . In the literature survey, orthosulfamuron has been analyzed neither as a single nor among multiple residue analysis in grains.…”

Determination of imazosulfuron persistence in rice crop and soil

“…Although there are several reports on the efficacy of imazosulfuron against various weeds in rice (Usui 2001;Akiyama et al 2002;Son and Rutto 2002), but very few reports on the methods of analysis and its environmental fate in rice agro-ecosystems. Some authors suggested a potential risk of sulfonylurea herbicides (Fletcher et al 1993;Peterson et al 1994;Fahl et al 1995), which are active at very low rate of application.…”

Development of a Method for the Simultaneous Determination of Six Sulfonylurea Herbicides in Wheat, Rice, and Corn by Liquid Chromatography–Tandem Mass Spectrometry

“…Coming with it is the requirement of the simultaneous quantitative determination of a few dozen SUHs residues in diverse biological matrices. Although in the past 20 years SUH residual analytical methods have been developed, high-performance liquid chromatography (HPLC) with an UV or diode array or MS detection system − was the most common approach because of the polar characteristic, low volatility, and thermal instability of SUHs. Capillary electrophoresis, − bioassays, − and enzyme-linked immunosorbent assay methods have also been tried.…”

“…Capillary electrophoresis, − bioassays, − and enzyme-linked immunosorbent assay methods have also been tried. In the above studies, the studied matrices were mainly environmental media, such as soil ,,,,, and water, ,,,, but there were very few reports on the analysis of cereals . Detection methods were dominated by single residue analysis, and the detection limit was at the mg kg –1 level.…”