title: Detection of polychlorinated biphenyls in transformer oils in Vietnam by multiphoton ionization mass spectrometry using a far-ultraviolet femtosecond laser as an ionization source.
abstract: Polychlorinated biphenyls (PCBs) in transformer and food oils were measured using gas chromatography combined with multiphoton ionization mass spectroscopy. An ultrashort laser pulse emitting in the far-ultraviolet region was utilized for efficient ionization of the analytes. Numerous signal peaks were clearly observed for a standard sample mixture of PCBs when the third and fourth harmonic emissions (267 and 200nm) of a femtosecond Ti:sapphire laser (800nm) were employed. The signal intensities were found to be greater when measured at 200nm compared with those measured at 267nm, providing lower detection limits especially for highly chlorinated PCBs at shorter wavelengths. After simple pretreatment using disposable columns, PCB congeners were measured and found to be present in the transformer oils used in Vietnam.
authors.affiliation: Institute of Physics, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam.
authors.forename: Vu Thi Thuy
authors.initials: VTT
authors.lastname: Duong
authors.affiliation: Institute of Physics, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam.
authors.forename: Vu
authors.initials: V
authors.lastname: Duong
authors.affiliation: Institute of Physics, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam.
authors.forename: Nghiem Thi Ha
authors.initials: NTH
authors.lastname: Lien
authors.affiliation: Laboratory of Chemistry, Graduate School of Design, Kyushu University, 4-9-1, Shiobaru, Minami-ku, Fukuoka 815-8540, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Imasaka
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Shinpei
authors.initials: S
authors.lastname: Shibuta
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Akifumi
authors.initials: A
authors.lastname: Hamachi
authors.affiliation: Institute of Physics, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam.
authors.forename: Do Quang
authors.initials: DQ
authors.lastname: Hoa
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan; Division of Optoelectronics and Photonics, Center for Future Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan. Electronic address: imasaka@cstf.kyushu-u.ac.jp.
authors.forename: Totaro
authors.initials: T
authors.lastname: Imasaka
keywords: Femtosecond laser; Mass spectrometry; Multiphoton ionization; Polychlorinated biphenyls; Transformer oil