高效液相層析結合感應耦合電漿質譜儀檢測飼料中砷型態

砷的生物毒性取決於化學結構形態，重金屬總砷濃度是飼料品質監測重要的檢測項目，用總量標準評估飼料中砷的污染情況和動物暴露水準，無法完全反映砷污染的的真實狀況。以溶劑(50% MeOH、25% EtOH和2% HNO3)微波輔助萃取及酵素(pepsin、amylase、bromelain及papain)超音波輔助萃取進行萃取效率比較，溶劑萃取以50% MeOH (萃取率=98.03%)及酵素萃取以bromelain (萃取率=99.45%)皆有較高萃取效果。選擇 bromelain搭配超音波萃取法具較短萃取時間、減少物種轉換及化學變化、高萃取效率及準確性等優點，為最適用之萃取方式。經方法確效，以高效液相層析儀分離物種，搭配感應偶合電漿質譜儀偵測定量，可於25分鐘內分離9種砷型態(AsB、AsC、AsⅢ、AsⅤ、DMA、MMA、p-ASA、4-HPAA及ROX)，並應用於飼料樣品分析。

關鍵字

微波輔助萃取；超音波輔助萃取；萃取效率；砷型態

並列摘要

The biological toxicities of arsenic species depend on their chemical structures and charge states. The total arsenic concentration in heavy metals is an important test item for feed quality monitoring. The measurement of total aresenic concentration is adequate to assess the contamination of arsenic in feed and the level of animal exposure, however it cannot fully reflect the state of arsenic pollution. By comparing the microwave-assisted extraction (MAE) with solvent in which three kinds of solvent including 50% MeOH, 25% EtOH and 2% HNO3 were used individually, and the ultrasonic-assisted extraction (UAE) with enzyme (using four kinds of proteases including pepsin, amylase, bromelain and papain) for optimization of extraction efficiency, the result indicated that the MAE using 50% MeOH and UAE with bromelain gave the highest extraction efficiency (98.03% and 99.45%, respectively). According to our result, the introduction of bromelain in UAE with enzyme showed a shorter extraction time, reducing species conversion, high extraction efficiency and accuracy, which implied that bromelain-based UAE is the most suitable extraction method. After sample preparation, the arsenic containing sample was analyzed using high-performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometer (ICP-MS). The method validation indicated that the separation of arsenic species using HPLC and the detection and quantification using ICP-MS can provide an efficient analysis of nine arsenic species (AsB, AsC, AsIII, AsV, DMA, MMA, p-ASA, 4-HPAA and ROX) within 25 minutes. Moreover, this method was further applied to feed sample analysis.