Multiresidue Analysis of Cotton Defoliant, Herbicide, and Insecticide Residues in Water by Solid-Phase Extraction and GC−NPD, GC−MS, and HPLC−Diode Array Detection

Abstract

A multiresidue procedure was developed for analysis of cotton pesticide and harvest-aid chemicals in water using solid-phase extraction and analysis by GC-NPD, GC-MS, and HPLC-DAD. Target compounds included the defoliants tribufos, dimethipin, thidiazuron; the herbicide diuron; and the insecticide methyl parathion. Three solid-phase extraction (SPE) media, octadecylsilyl (ODS), graphitized carbon black (GCB), and a divinylbenzene-N-vinyl pyrollidine copolymer (DVBVP), were evaluated. On GCB and ODS, recoveries varied depending on compound type. Recoveries were quantitative for all compounds on DVBVP, ranging from 87 to 115% in spiked deionized water and surface runoff. The method detection limit was less than 0.1 microg L(-)(1). SPE with DVBVP was applied to post-defoliation samples of surface runoff and tile drainage from a cotton research plot and surface runoff from a commercial field. The research plot was defoliated with a tank mixture of dimethipin and thidiazuron, and the commercial field, with tribufos. Dimethipin was detected (1.9-9.6 microg L(-)(1)) in all research plot samples. In the commercial field samples, tribufos concentration ranged from 0.1 to 135 microg L(-)(1). An exponentially decreasing concentration trend was observed with each successive storm event.

Linear Modulated Stochastic Resonance Algorithm Applied to Determination of Thidiazuron Residue in Water Using Stochastic Resonance

“…The same optimization steps mentioned above were used and the parameters a, b, a, and b were set to 0.03, 0.001, 0.05, and 20.19, respectively. The LOD and LOQ were estimated to be 2.5 and 10 ng/l, respectively, which were much lower than the values reported in the literatures (Potter et al 2000(Potter et al , 2003Li et al 2001) and satisfied the detection limit requirement of the European Union. The chromatograms obtained by LSRA with the originals at the concentrations of 10, 30, 40, 50, 60, 80, and 100 ng/l are compared in Fig.…”

“…It means that an analytical method should reach a detection limit lower than around four times this value in order to reduce the possibility of false positive findings (LeConseil 1998). Potter et al (2000Potter et al ( , 2003 reported the method detection limit of thidiazuron at the exact 0.1 mg/l using solid phase extraction (SPE) and HPLC-diode array detection (HPLC-DAD), but the same method failed to achieve that concentration level in the research work of Li et al (2001). To our knowledge, there has not been any better result reported for residue analysis of thidiazuron in water.…”

Enhancement of Analytical Method for Thidiazuron Residues and Monitoring of its Residues in Agricultural Commodities

“…특히, thidiazuron은 purine계 합성생장 조정제보다도 더 생리 활성이 더 강한 것으로 알려져 있으며, 여러 목본성 식물 증식에도 사용되고 있다 (Green, 1994; Open Access Research Article Arndt and Rusch, 1985). Thidiazuron 분석법 연구에 대한 보고로 물, 토양 등 환 경매체에 대한 잔류분석과 (Potter et al, 2000;Guo et al, 2010), 목화씨 (Cai et al, 2009;Guo et al, 2005), 멜론 (Wang et al, 2010) (Fig. 4.).…”

Effects of functionalized fullerenes on bifenthrin and tribufos toxicity to Daphnia magna: Survival, reproduction, and growth rate

“…Previous studies have shown bifenthrin to be toxic to D. magna (96-h LC50 ¼ 0.32 À 1.60 mg/L) [20,21]. Tribufos is a cotton defoliant used in agricultural areas in the Mississippi alluvial plain, the southeastern United States, Texas, California [21], and Georgia [22]. It is a cholinesterase inhibitor and has been shown to be toxic to D. magna (48-h LC50 ¼ 6.8 À 110.0 mg/L) [21].…”