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A new method for sensitively and selectively detecting chemical warfare agents (CWAs) in air was developed using counter-flow introduction atmospheric pressure chemical ionization mass spectrometry (MS). Four volatile and highly toxic CWAs were examined, including the nerve gases sarin and tabun, and the blister agents mustard gas (HD) and Lewisite 1 (L1). Soft ionization was performed using corona discharge to form reactant ions, and the ions were sent in the direction opposite to the airflow by an electric field to eliminate the interfering neutral molecules such as ozone and nitrogen oxide. This resulted in efficient ionization of the target CWAs, especially in the negative ionization mode. Quadrupole MS (QMS) and ion trap tandem MS (ITMS) instruments were developed and investigated, which were movable on the building floor. For sarin, tabun, and HD, the protonated molecular ions and their fragment ions were observed in the positive ion mode. For L1, the chloride adduct ions of L1 hydrolysis products were observed in negative ion mode. The limit of detection (LOD) values in real-time or for a 1 s measurement monitoring the characteristic ions were between 1 and 8 μg/m(3) in QMS instrument. Collision-induced fragmentation patterns for the CWAs were observed in an ITMS instrument, and optimized combinations of the parent and daughter ion pairs were selected to achieve real-time detection with LOD values of around 1 μg/m(3). This is a first demonstration of sensitive and specific real-time detection of both positively and negatively ionizable CWAs by MS instruments used for field monitoring.

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This letter reports on the fabrication and investigation of ferroelectric epitaxial Pb(Zr,Ti)O3(PZT)∕Pt films on Si substrates using epitaxial γ-Al2O3 buffer layer for Si integrated ferroelectric devices. (001) and (111) epitaxial γ-Al2O3 films were grown on Si(001) and Si(111) substrates, respectively, using chemical vapor deposition. PZT films with various compositions were epitaxially grown on epitaxial Pt coated substrates using a sol-gel method. Epitaxial PZT films exhibited better ferroelectric and pyroelectric properties than polycrystalline PZT films. In particular, maximum pyroelectric coefficients of the epitaxial films were obtained, with values of 1.8×10−8C∕cm2K for the PZT(001) film with a Zr∕Ti ratio of 40∕60 and 1.4×10−8C∕cm2K for the PZT(111) film with a Zr∕Ti ratio of 52∕48.

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