Dissipation and residue of metalaxyl and cymoxanil in pepper and soil.

Environmental monitoring and assessment (2014-05-06)
Xiangyun Liu, Yan Yang, Ying Cui, Huijun Zhu, Xiong Li, Zhining Li, Kankan Zhang, Deyu Hu
ABSTRACT

A simple and accurate method of determining metalaxyl and cymoxanil in pepper and soil was developed by ultra-performance liquid chromatography-photodiode array detection. The limits of detection were 0.015 mg/kg for metalaxyl and 0.003 mg/kg for cymoxanil. The limits of quantification were 0.05 mg/kg for metalaxyl in pepper and soil as well as 0.01 mg/kg for cymoxanil in pepper and soil. Recoveries of pepper and soil were investigated at three spiking levels and ranged within 77.52 to 102.05 % for metalaxyl and 87.15 to 103.21 % for cymoxanil, with relative standard deviations below 9.30 %. For field experiments, the half-lives of metalaxyl were 3.2 to 3.9 days in pepper and 4.4 to 9.5 days in soil at the three experimental locations in China. At harvest, pepper samples were found to contain metalaxyl and cymoxanil well below the maximum residue limit MRLs of the European Union (EU) following the recommended dosage and the interval of 21 days after last application.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Acetonitrile, suitable for HPLC, gradient grade, ≥99.9%
Sigma-Aldrich
Acetonitrile, anhydrous, 99.8%
Sigma-Aldrich
Acetonitrile, HPLC Plus, ≥99.9%
Sigma-Aldrich
Acetonitrile, ACS reagent, ≥99.5%
Sigma-Aldrich
Acetonitrile, for HPLC, for UV, ≥99.9% (GC)
Sigma-Aldrich
Acetonitrile, suitable for HPLC, gradient grade, ≥99.9%
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
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Acetonitrile solution, contains 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
Acetonitrile, suitable for HPLC-GC, ≥99.8% (GC)
Supelco
Metalaxyl, PESTANAL®, analytical standard
Supelco
Acetonitrile, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Acetonitrile, analytical standard
Supelco
Cymoxanil, PESTANAL®, analytical standard
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Acetonitrile, biotech. grade, ≥99.93%
Sigma-Aldrich
Acetonitrile, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥99.5% (GC)
Millipore
Acetonitrile solution, suitable for HPLC, acetonitrile:water 5:95% (v/v), 10 mM Ammoniumbicarbonate, pH 10,0
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Acetonitrile, ReagentPlus®, 99%
Supelco
Residual Solvent - Acetonitrile, Pharmaceutical Secondary Standard; Certified Reference Material
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Acetonitrile, electronic grade, 99.999% trace metals basis
Sigma-Aldrich
Acetonitrile, ≥99.5% (GC)
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Acetonitrile, suitable for DNA synthesis, ≥99.9% (GC)
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (v/v) trifluoroacetic acid
Metalaxyl, analytical standard
Sigma-Aldrich
Acetonitrile, for preparative HPLC, ≥99.8% (GC)