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大気中に存在する種々の農薬を低濃度まで正確に測定する方法として, 高分離能ガスクロマトグラフ/高分解能質量分析計 (HRGC/HRMS) の適用を検討した. 質量分析計の分解能を変えて標準溶液でのシグナル-ノイズ比 (SN比) を比較したところ, 高分解能 (R=5000) において28種類中21種類の農薬でSN比が向上し, 定量下限を下げることができた. また, 実際の試料ではクロマトグラム上で種々の妨害物質の影響を受けやすいが, 分解能を向上させることによって, ほとんどの農薬に対しこれらの妨害物質の影響を除くことができた. この方法を実際の大気環境の測定に応用した. 10m3の環境大気を活性炭チューブで捕集し, 抽出後フロリジルカラムによる分画を行い, 1mlまで濃縮した試料に対し, 10-3μg/m3オーダーまで大気中農薬の測定が可能であった.

An ultrasonic extraction method was evaluated for a GC/MS determination of polyaromatic hydrocarbons (PAHs) and n-alkanes in airborne particulate matter, compared with the Soxhlet extraction method. Three airborne particulate samples collected at an industrial area of Kitakyushu City, a heavy traffic area of Kawasaki City, and Urban Dust (Standard Reference Material 1649) were extracted for seven PAHs and eight n-alkanes by both the ultrasonic extraction method with cyclohexane-ethanol (3 : 1) and Soxhlet extraction method with benzene-ethanol (3 : 1). Vehicle Exhaust Particulate (NIES No. 8) was also extracted for the compounds by the two methods. The results of the target compounds by the ultrasonic extraction method well agreed with those by the Soxhlet extraction method, except for the vehicle exhaust particulate.

農薬90種及びその分解化合物10物質の合計100化合物を対象として,環境水中の粒子状物質(PM)中に存在している農薬の分析法を確立した.試料500mlを1μmガラス繊維濾紙で濾過し,濾液を更に0.5μm親水性ポリテトラフルオロエチレン(PTFE)濾紙で濾過した.各々の濾紙にアセトン24mlを加えて20分間超音波抽出後,遠心上澄みを20ml分取し,1mlに減圧濃縮してGC/MS法により測定した.対象農薬を河川水へ添加し,本法により河川水中のPMへの農薬の分配率を測定した結果, PMに3%以上分配された農薬は13種であり,20%以上の分配率があったのはエトフェンプロックス, ベンフルラリン及びトリフルラリンであった.本法による各農薬の回収率は74～109%,相対標準偏差は1農薬を除いて10%以内であり,PMへの分配率が高かった農薬も良好に測定することができた. 又,本法を環境試料測定に適用した結果,PMからエトフェンプロックス及びピリブチカルブが検出された.

A gas chromatography-mass spectrometric (GC/MS) method has bean developed for the simultaneous determination of hazardous chemicals. First, a monitoring system of 90 pesticides and 10 transformation products in river water was established; the pesticides in the dissolved phase were extracted with the solid phase and those in the suspended phase were extracted ultrasonically. Second, an optimum analytical conditions of headspace method were examined to the determination of 53 volatile organic compounds (VOCs) in river water and sediment. Last, an ultrasonic extraction method using ethanol-cyclohexane (1 : 3) was evaluated for the determination of seven polycyclic aromatic hydrocarbons (PAHs) and eight n-alkans in airborne particulate matter.These methods were applied to monitoring the target compounds in Niigata Prefecture. First, in monitoring pesticides in Shinano River, 53 compounds were detected, and the distribution ratios of the pesticides from dissolved phases to the suspended phase seem to depend on the concentrations and properties of the compounds. Second, VOCs were determined for 29 compounds from 16 rivers, and the number of detected VOCs was larger in the winter than in the summer. Last, the concentration levels of PAHs and n-alkanes in airborne particulate matter were evaluated, and anthropogenic sources, including traffic, were the major contributions to the particulates.The results of this study will be available for the monitoring and control of hazardous chemicals suspected to damage human health and ecosystems.