Real-Time PCB Monitoring Using Time-of-Flight Mass Spectrometry with Picosecond Laser Ionization

Deguchi, Yoshihiro; Dobashi, Shinsaku; Fukuda, Norihiro; Shinoda, Katsuhiko; Morita, Masatoshi

doi:10.1021/es034257j

Cited by 27 publications

(14 citation statements)

References 16 publications

(18 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…10,38 In the future, the long-term reliability of the monitoring system will be verified, and practical applications will be pursued as innovative tools for safety management in various types of PCB treatment plants. ANALYTICAL SCIENCES JANUARY 2004, VOL.…”

Section: Resultsmentioning

confidence: 99%

Real-Time Measurements of Polychlorinated Biphenyls Using Laser Ionization Time-of-Flight Mass Spectrometry

et al. 2004

Self Cite

View full text Add to dashboard Cite

Polychlorinated aromatic hydrocarbons include many hazardous compounds, 1-5 such as PCBs (polychlorinated biphenyls), PCDDs (polychlorinated dibenzodioxins), PCDFs (polychlorinated dibenzofurans), polyhexachlorobenzene and pentachlorophenol. For protection from such chemicals, it is necessary to rapidly monitor their concentrations. Especially in PCB disposal plants, pollution of the surrounding environment must be strictly prevented, giving a strong imperative for the development of real-time measurement technology for PCB concentration monitoring.The conventional methods, such as GC-ECD (gas chromatograph with an electron-captured detector) and GC-MS (gas chromatograph-mass spectrometry), require extensive analysis time (several days per sample) and are not suitable for the above requirements.Recently, the development of the pulsed-laser technique has enabled us to measure aromatic hydrocarbons quite rapidly. In particular, the LI-TOFMS technique is expected to be a powerful method for on-line, selective and sensitive measurements. In the work reported here, real-time (1 min) LI-TOFMS measurements were carried out on gaseous 2 -4 chlorinated PCBs. With respect to laser ionization (as the key technology underpinning this method), in particular, the efforts to determine the laser wavelength and the pulse duration for PCB ionization resulted in the establishment of a technique having sufficient sensitivity (< 0.01 mg/Nm 3 ) for real-time PCBs measurements. Principle 2·1 Laser ionizationThe laser ionization principle used in this study is known as resonance-enhanced two-photon ionization. 6-10 A three-level ionization model (energy diagram) 27,28 is presented in Fig. 1, illustrating the principle behind this method. Here, X indicates the ground state of a molecule, R the exited state, and C the ionization potential. Molecules are excited to induce the R⇔X transition and ionized by the C←R transition. The notation "a" is the rate constant for the R⇔X transition, and "b" is that for the R←C transition. These are related to the number of photons (F) in terms of a∝F and b∝F. Notation kr is the rate constant for spontaneous emission, while knr indicates that for the nonradiative decay processes in state R. In the present study, Real-Time Measurements of Polychlorinated Biphenyls Using Laser Ionization Time-of-Flight Mass SpectrometryShinsaku DOBASHI, † Yoshihiro DEGUCHI, Takahiro KUBOTA, and Katsuhiko SHINODA Nagasaki Research and Development Center, Mitsubishi Heavy Industries Ltd., Japan Polychlorinated biphenyls (PCBs) are hazardous compounds for which there are few methods involving real-time measurement. Recently, the development of the pulsed-laser technique has enabled us to measure aromatic hydrocarbons quite rapidly. In particular, the LI-TOFMS (laser ionization time of flight mass spectrometry) technique is expected to be a powerful method for on-line, selective and sensitive measurements. In the context of developing a highly selective and sensitive technique, the effective laser wavelength and pulse du...

show abstract

Section: Resultsmentioning

confidence: 99%

Real-Time Measurements of Polychlorinated Biphenyls Using Laser Ionization Time-of-Flight Mass Spectrometry

et al. 2004

Self Cite

View full text Add to dashboard Cite

show abstract

“…It was found that a laser emitting at this wavelength was more effective for ionizing PCBs than a laser emitting at 280, 300, or 320 nm. 78,79 By taking into account the general concentration of PCDD/Fs in a flue gas, these compounds can be detected once per hour using this "quasireal-time monitoring system" without any pretreatment, including the elution time required for a GC run.…”

Section: Discussionmentioning

confidence: 99%

Sensitive and Selective Analysis of Polychlorinated Dibenzo-p-dioxins/Dibenzofurans and Their Precursors by Supersonic Jet/Resonance-Enhanced Multiphoton Ionization/Time-of-Flight Mass Spectrometry

Uchimura

2005

ANAL. SCI.

View full text Add to dashboard Cite

“…43) New findings presented here include the e$cient trapping of laser-ionized PCB ions using the dynamic trapping time-of-flight mass spectrometry (TOFMS), as well as the simulation of electric field control conditions for e$cient trapping, and observation of the e#ectiveness of reducing the speed of the ions introduced into the trap apparatus. 41), 42) Evaluations of accuracy based on comparisons with the results of the conventional method (gas sampling/gas chromatography mass spectrometry; gas sampling/ GC-MS) demonstrated a coe$cient of variation of ῌ30῍.…”

Section: )῏68)mentioning

confidence: 99%

Automated Analysis of Persistent Organic Pollutants in the Gas Phase by Laser Ionization Mass Spectrometry

Dobashi

Yamaguchi

Izawa

et al. 2010

J. Mass Spectrom. Soc. Jpn.

Self Cite

View full text Add to dashboard Cite

Persistent organic pollutants (POPs) are toxic chemicals that adversely a#ect human health and the environment around the world. The detection and evaluation of small amounts of POPs require methods with both high precision and high chemical selectivity. Conventional methods involve a number of preparatory steps and time-consuming analysis and are not suitable for the abovementioned purposes. Hence, new automated analysis methods are required for on-line detection and rapid analysis of POPs. In this paper, mass spectrometry with resonance-enhanced multi-photon ionization (REMPI) is performed to obtain information about the automated analysis of POPs in the gas-phase with on-line detection. Dynamic trapping time-of-flight mass spectrometry (TOFMS) was performed with su$cient selectivity and sensitivity for rapid analysis of polychlorinated biphenyls (PCBs) in the gas phase. Compared to normal trapping, the use of dynamic trapping enabled ion signal intensity to be increased by a factor of greater than 10. The detection limit at 1 min was ῍1 ppbV, and the accuracy also correlated well with the results of conventional analysis. Based on these results, an automated monitoring system was developed for automated analysis of PCBs. It was confirmed that this monitoring system was capable of analyzing PCB concentration without being influenced by main gas components or various coexisting substances, even under conditions characterized by exhaust gas and the work environment atmosphere. PCB concentration in PCB waste plants, which is substantially lower than the 0.10 mg/m 3 N specified in statutory regulations, could be analyzed within 1 min. It was possible to make continuous long-term analysis for over 2,000 h (120,000 points).

show abstract

Real-Time PCB Monitoring Using Time-of-Flight Mass Spectrometry with Picosecond Laser Ionization

Cited by 27 publications

References 16 publications

Real-Time Measurements of Polychlorinated Biphenyls Using Laser Ionization Time-of-Flight Mass Spectrometry

Real-Time Measurements of Polychlorinated Biphenyls Using Laser Ionization Time-of-Flight Mass Spectrometry

Sensitive and Selective Analysis of Polychlorinated Dibenzo-p-dioxins/Dibenzofurans and Their Precursors by Supersonic Jet/Resonance-Enhanced Multiphoton Ionization/Time-of-Flight Mass Spectrometry

Automated Analysis of Persistent Organic Pollutants in the Gas Phase by Laser Ionization Mass Spectrometry

Contact Info

Product

Resources

About