title: Identification of a novel low-level impurity in fungicide pyraclostrobin by high-performance liquid chromatography/tandem mass spectrometry.
abstract: Pyraclostrobin is one kind of new type methoxy acrylate fungicides that has been widely used in agriculture at present, with a lot of advantages including broad spectrum, high efficiency and high selectivity. In this work, a novel low-level impurity in the pyraclostrobin at about 0.2% was separated and characterized by high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS). Firstly, the impurity was speculated to possess the same skeleton structure as the main product pyraclostrobin while the methyl group on the methyl ester was substituted to be CH2CH2Cl on the basis of the on-line multi-stage mass spectrometric behaviors compared with that of pyraclostrobin. Then the accurate molecular weight and element composition of target impurity was verified to be C20H19Cl2N3O4by high resolution mass spectrometry. Finally, the proposed structure was further confirmed by the1H NMR data.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, China.
authors.forename: Kaimin
authors.initials: K
authors.lastname: Xia
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, China.
authors.forename: ShanShan
authors.initials: S
authors.lastname: Shen
authors.affiliation: Laprode Analysis Co., Ltd., Hangzhou, China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Laprode Analysis Co., Ltd., Hangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shang
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, China. Electronic address: panyuanjiang@zju.edu.cn.
authors.forename: Yuanjiang
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
mesh_terms: D002219:Carbamates / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004340:Drug Contamination; D005659:Fungicides, Industrial / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation; D011720:Pyrazoles / Q000737:chemistry*; D000073739:Strobilurins; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D002219:Carbamates; D005659:Fungicides, Industrial; D011720:Pyrazoles; D000073739:Strobilurins; C513428:pyrachlostrobin
keywords: HPLC/MS; Impurity; Pyraclostrobin; Tandem MS analysis