Determination of paraquat and diquat in human body fluids by high-performance liquid chromatography/tandem mass spectrometry.
Paraquat (PQ) and diquat (DQ) in human whole blood and urine were analyzed by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) with positive ion electrospray ionization (ESI). The compounds were extracted with Sep-Pak C18 cartridges from whole blood and urine samples containing ethyl paraquat as an internal standard. The separation of PQ and DQ was carried out using ion-pair chromatography with heptafluorobutyric acid in 20 mM ammonium acetate and acetonitrile gradient elution for successful coupling with MS. Both compounds formed base peaks due to [M-H]+ ions by HPLC/ESI-MS and the product ions produced from each [M-H]+ ion by HPLC/MS/MS. Selective reaction monitoring (SRM) showed much higher sensitivity for both body fluids. Therefore, a detailed procedure for the detection of compounds by SRM with HPLC/MS/MS was established and carefully validated. The recoveries of PQ and DQ were 80.8-95.4% for whole blood and 84.2-96.7% for urine. The calibration curves for PQ and DQ showed excellent linearity in the range of 25-400 ng ml(-1) of whole blood and urine. The detection limits were 10 ng ml(-1) for PQ and 5 ng ml(-1) for DQ in both body fluids. The intra- and inter-day precision for both compounds in whole blood and urine samples were not greater than 13.0%. The data obtained from the determination of PQ and DQ in rat blood after oral administration of the compounds are also presented.
Lee
Xiao-Pen
XP
Department of Legal Medicine, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
Kumazawa
Takeshi
T
Fujishiro
Masaya
M
Hasegawa
Chika
C
Arinobu
Tetsuya
T
Seno
Hiroshi
H
Ishii
Akira
A
Sato
Keizo
K
D000818:Animals; D001826:Body Fluids / Q000737:chemistry; D002624:Chemistry, Clinical / Q000295:instrumentation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004178:Diquat / Q000032:analysis / Q000097:blood* / Q000652:urine; D006540:Herbicides / Q000032:analysis / Q000097:blood* / Q000652:urine; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D010269:Paraquat / Q000032:analysis / Q000097:blood* / Q000652:urine; D051381:Rats
D006540:Herbicides; D004178:Diquat; D010269:Paraquat