title: Determination of orthophthalaldehyde in air using 2,4-dinitrophenylhydrazine-impregnated silica cartridge and high-performance liquid chromatography.
abstract: A new method is described for the determination of orthophthalaldehyde in air which is used for the disinfection of various instruments (e.g. endoscopes) in hospital. Orthophthalaldehyde in air was collected with a silica gel cartridge impregnated with acidified 2,4-dinitrophenylhydrazine (DNPH-cartridge) and derivatives were analyzed by high-performance liquid chromatography (HPLC). In this study, the derivatization was examined by comparing the process with three phthalaldehyde isomers (ortho-, iso- and tere-). In the case of iso- and tere-phthalaldehyde, derivatives synthesized with excess of aldehyde consisted mainly of mono-derivatives, and derivatives synthesized with excess of DNPH consisted mainly of bis-derivative. In the case of orthophthalaldehyde, derivative consisted of only bis-derivative and mono-derivative was never observed under any conditions. Orthophthalaldehyde was completely retained by the DNPH-cartridge during air sampling, however, the derivatization reaction was incomplete and unreacted orthophthalaldehyde was flushed from the cartridge during the subsequent solvent extraction process. Unreacted orthophthalaldehyde and DNPH reacted again in the extraction solvent solution. Immediately after the solvent extraction, both mono- and bis-DNPhydrazone derivatives of orthophthalaldehyde were present in the solution. However, over time, the mono-derivative decreased and bis-derivative increased until only the bis-derivative was left allowing accurate determination of the orthophthalaldehyde concentration. The transformation of mono-derivative to bis-derivative was faster in polar aprotic solvents such as acetonitrile, dimethyl sulfoxide and ethyl acetate. Transformation was found to occur most quickly in acetonitrile solvent and was completed in 4 h in this case. It was possible to measure orthophthalaldehyde in air as bis-derivative using a DNPH impregnated silica cartridge and HPLC analysis.
authors.affiliation: Faculty of Engineering, Chiba University 1-33, Yayoi-Cho, Inage-Ku, Chiba City, Chiba 263-8522, Japan. ucym@tu.chiba-u.ac.jp
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Uchiyama
authors.forename: Erika
authors.initials: E
authors.lastname: Matsushima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tokunaga
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Otsubo
authors.forename: Masanori
authors.initials: M
authors.lastname: Ando
mesh_terms: D000388:Air / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D010659:Phenylhydrazines / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D009764:o-Phthalaldehyde / Q000032:analysis*
chemical_list: D010659:Phenylhydrazines; C004787:2,4-dinitrophenylhydrazine; D009764:o-Phthalaldehyde; D012822:Silicon Dioxide