酸触媒を用いないDNPH誘導体化／高速液体クロマトグラフィーによる環境大気中アクロレインの定量

摘要

The standard method for determining gaseous aldehydes involves the collection of the aldehydes on a 2,4-dinitrophenyl hydrazine (DNPH)-coated silica gel cartridge, followed by solvent extraction of the cartridge and analysis of the aldehyde derivatives using high-performance liquid chromatography (HPLC). However, acid catalysis is required for a fast and quantitative derivatization reaction, and the DNPH derivatives of α,β-unsaturated aldehydes, such as acrolein, disappear during storage of the acidified DNPH-coated cartridges. In this paper, we describe a new method that involves the collection of acrolein and other lower aldehydes on a non-acidified DNPH-coated silica-gel cartridge. Using this method, we were able to carry out highly sensitive simultaneous sampling, as indicated by the quantitative collection of acrolein and other lower aldehydes on the cartridge. The acrolein hydrazone was stable on the cartridge at room temperature, and the gaseous acrolein concentrations measured in a test atmosphere were in good agreement with those obtained by means of the traditional DNPH-solution method. In addition, the new method was tested on an ambient air sample. The operational procedure for the non-acidified DNPH-coated cartridge is nearly the same as that for the standard DNPH/HPLC method. This new method will permit the determination of acrolein, formaldehyde, and acetal-dehyde in atmospheric environmental applications.%環境大気中のアルデヒド?ケトン類を測定する手法としrnて，リン酸酸性下におけるDNPH（2,4-Dinitrophenylrnhydrazine）誘導体化法により試料を採取し，そのヒドラrnゾン（DNPH誘導体）を高速液体クロマトグラフィーrn（HPLC）で分析する方法が公定法として広く用いられていrnる．輔集基材であるDNPH含浸シリカ固相カートリッrnジ（DNPHカートリッジ）は，1986年頃に開発され，1991rn年より市販化されたが，開発当初よりアクロレインなどのrn不飽和カルポニルの定量性に問題があることが指摘されてrnおり，解決が難しいとされていた．