title: Method for measurement of the quaternary amine compounds paraquat and diquat in human urine using high-performance liquid chromatography-tandem mass spectrometry.
abstract: We have developed a highly selective and sensitive analytical method to quantify paraquat and diquat by use of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample preparation includes solid phase extraction that uses weak cation exchange cartridges. These highly charged dual quaternary amines were not retained by standard reversed phase columns, but they could be adequately separated through HPLC with a HILIC column. The detection was carried out with a triple quadrupole mass spectrometer with an electrospray ionization probe in positive ion mode in multiple reaction monitoring. Repeated analysis in human urine samples spiked with low (5 ng/ml), medium (15 ng/ml), and high (30 ng/ml) concentrations of the analytes yielded relative standard deviations of less than 9%. The extraction efficiencies ranged from 77.7% to 94.2%. The limits of detection were in the range of 1 ng/ml.
authors.affiliation: Centers for Disease Control and Prevention, National Center for Environmental Health, Division of Laboratory Sciences, Atlanta, GA, USA.
authors.forename: Ralph D
authors.initials: RD
authors.lastname: Whitehead
authors.forename: M Angela
authors.initials: MA
authors.lastname: Montesano
authors.forename: Nayana K
authors.initials: NK
authors.lastname: Jayatilaka
authors.forename: Brian
authors.initials: B
authors.lastname: Buckley
authors.forename: Bozena
authors.initials: B
authors.lastname: Winnik
authors.forename: Larry L
authors.initials: LL
authors.lastname: Needham
authors.forename: Dana Boyd
authors.initials: DB
authors.lastname: Barr
mesh_terms: D002411:Cation Exchange Resins; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004178:Diquat / Q000652:urine*; D006801:Humans; D057230:Limit of Detection; D010269:Paraquat / Q000652:urine*; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D002411:Cation Exchange Resins; D004178:Diquat; D010269:Paraquat