LC-MS/MS を用いた迅速で簡便な飲料中の残留農薬一斉分析法の実用化に向けての検討

摘要

A rapid and simple multi-residue method for determination of pesticides has been applied to drinking water and beverages. To a disposable polypropylene tube containing 10.0 g sample, 20 mL acetonitrile was added and the mixture was shaken vigorously for 1 min to extract pesticides. Then, 1 g sodium chloride and 4 g magnesium sulfate anhydrous were added, followed by vigorous shaking for 1 min and centrifugation to obtain the organic phase. The organic phase was processed with a graphite carbon black/PSA solid phase column. After concentration and reconstitution with 25% methanol containing aqueous solution, the test solution was analyzed with LC-MS/MS. Recovery tests of 91 pesticides fortified (0.02 μg/g) in 35 kinds of drinking water and beverages were conducted. The decline of recoveries in alcoholic beverages is considered to be due to the increase of organic phase volume owing to ethanol included in the alcoholic beverages. A simulation study was carried out with simulated alcoholic beverages, which consisted of 50% grape juice, with various amounts of ethanol and water, to examine pesticides recoveries and volume of the organic phase. The results suggested this method would be applicable both to alcoholic beverages containing less than 10% ethanol and to alcoholic beverages containing over 10% ethanol after dilution with water to below 10% ethanol prior to the addition of acetonitrile. A sample could be processed and analyzed by LC-MS/MS within 2 h. Thus, this method should be useful for monitoring and screening pesticide residues in drinking water and various beverages.%LC-MS/MS を用いた迅速で簡便な飲料中の残留農薬一斉分析法の実用化に向けて検討を行った．試料にアセトニトリルを混合し，塩析・脱水処理を経て固相カラム（グラファイトカーボン/PSA）で精製しLC-MS/MS で定量した．35種類の飲料で検討した結果，アルコール度数の高い飲料以外は適用可能であった．アルコール飲料の回収率は低下した．この原因は，塩析・脱水後の有機相へのエタノール混入による液量増加と推測された．そこで，ぶどう果汁に任意の量のエタノールを添加して作製した模擬アルコール飲料を用いて検証し，本法が適用可能なエタノール濃度を10％未満とした．アルコール度数の高い飲料は水で希釈を行い適用できた．本法により1試料当たり前処理から定量まで約2時間で可能で，スクリーニング分析法として活用できる．