title: [Simultaneous determination of 10 unapproved sedative drugs in feeds by ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry].
abstract: A new analytical method using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was developed for screening and confirmation of 10 unapproved sedative drugs in feeds. The samples were extracted using the solution of methanol-0.1 mol/L HCl (9:1, v/v), and the extracts were centrifuged and then directly purified through MCX cartridges. The identification and detection were achieved in positive electrospray ionization (ESI) mode using Q-TOF-MS. The potential of UPLC-Q-TOF MS for confirmatory analysis was shown by determining the accurate mass of all the compounds and fragment ions upon collision-induced-dissociation (CID) at different energies. The extra mass measurement errors for all the sedative drugs were found to be within 5 ppm. The calibration graphs were linear in the concentration range of 5-100 microg/L with the correlation coefficients more than 0.99 for the 10 drugs. The limits of quantification (LOQ, S/N = 10) were 8 microg/kg for nitrazepam, zolpidem and thioridazine; 10 microg/kg for thriazolam, estazolam, diazepam, promethazine, chlorpromazine and midazolam; 20 microg/kg for clozapine. The recoveries for all the compounds in feeds were 60.6%-108.5% with the relative standard deviations less than 10% at the spiked levels of LOQ, 2LOQ and 4LOQ.
authors.affiliation: Agricultural University of Hebei, Baoding 071001, China. xuchengbao123@126.com
authors.forename: Chengbao
authors.initials: C
authors.lastname: Xu
authors.forename: Ran
authors.initials: R
authors.lastname: Suo
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Chu
authors.forename: Fei
authors.initials: F
authors.lastname: Ding
authors.forename: Yun
authors.initials: Y
authors.lastname: Ling
authors.forename: Minli
authors.initials: M
authors.lastname: Yang
authors.forename: Li
authors.initials: L
authors.lastname: Sun
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D014150:Antipsychotic Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003975:Diazepam / Q000032:analysis; D006993:Hypnotics and Sedatives / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D009567:Nitrazepam / Q000032:analysis; D011725:Pyridines / Q000032:analysis; D013881:Thioridazine / Q000032:analysis; D000077334:Zolpidem
chemical_list: D014150:Antipsychotic Agents; D006993:Hypnotics and Sedatives; D011725:Pyridines; D000077334:Zolpidem; D009567:Nitrazepam; D013881:Thioridazine; D003975:Diazepam