title: Feasibility and application of an HPLC/UVD to determine dinotefuran and its shorter wavelength metabolites residues in melon with tandem mass confirmation.
abstract: A new analytical method was developed for dinotefuran and its metabolites, MNG, UF, and DN, in melon using high-performance liquid chromatography (HPLC) coupled with an ultraviolet detector (UVD). Due to shorter wavelength, lower sensitivity to UV detection, and high water miscibility of some metabolites, QuEChERs acetate-buffered version was modified for extraction and purification. Mobile phases with different ion pairing or ionisation agents were tested in different reverse phase columns, and ammonium bicarbonate buffer was found as the best choice to increase the sensitivity of target analytes to the UV detector. After failure of dispersive SPE clean-up with primary secondary amine, different solid phase extraction cartridges (SPE) were used to check the protecting capability of analytes against matrix interference. Finally, samples were extracted with a simple and rapid method using acetonitrile and salts, and purified through C(18)SPE. The method was validated at two spiking levels (three replicates for each) in the matrix. Good recoveries were observed for all of the analytes and ranged between 70.6% and 93.5%, with relative standard deviations of less than 10%. Calibration curves were linear over the calibration ranges for all the analytes with r(2)≥ 0.998. Limits of detection ranged from 0.02 to 0.05 mg kg(-1), whereas limits of quantitation ranged from 0.06 to 0.16 mg kg(-1) for dinotefuran and its metabolites. The method was successfully applied to real samples, where dinotefuran and UF residues were found in the field-incurred melon samples. Residues were confirmed via LC-tandem mass spectrometry (LC-MS/MS) in positive-ion electrospray ionisation (ESI(+)) mode.
authors.affiliation: Natural Products Chemistry Laboratory, Biotechnology Research Institute, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
authors.forename: Md Musfiqur
authors.initials: MM
authors.lastname: Rahman
authors.forename: Jong-Hyouk
authors.initials: JH
authors.lastname: Park
authors.forename: A M
authors.initials: AM
authors.lastname: Abd El-Aty
authors.forename: Jeong-Heui
authors.initials: JH
authors.lastname: Choi
authors.forename: Angel
authors.initials: A
authors.lastname: Yang
authors.forename: Ki Hun
authors.initials: KH
authors.lastname: Park
authors.forename: Md
authors.initials: M
authors.lastname: Nashir Uddin Al Mahmud
authors.forename: Geon-Jae
authors.initials: GJ
authors.lastname: Im
authors.forename: Jae-Han
authors.initials: JH
authors.lastname: Shim
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D019662:Cucurbitaceae / Q000737:chemistry* / Q000378:metabolism; D005506:Food Contamination / Q000032:analysis*; D006146:Guanidines / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D007306:Insecticides / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
chemical_list: D006146:Guanidines; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010573:Pesticide Residues; C465368:dinotefuran