基質輔助雷射脫附游離影像質譜術(Matrix-assisted laser desorption/ionization imaging mass spectrometry ，MALDI- IMS)是一種可呈現有機化合物組織切片上空間分佈的質譜影像技術。然而,該技術在檢測金屬元素方面面臨挑戰。本研究中，將螯合試劑1-(2-pyridylazo)-2-naphthol (PAN)添加到傳統的MALDI基質(即α-cyano-4-hydroxycinnamic acid and 2,5-dihydroxybenzoic acid)中，以改善對金屬元素的檢測能力,並運用MALDI-IMS檢測阿拉伯芥(Arabidopsis thaliana)幼苗中的有機代謝物與金屬分布。
實驗結果顯示，PAN基質能夠與多種金屬如Li、Na、K、Cu、Pb、Mn、Fe、Co、Ni等形成穩定的錯合物，並在MALDI-TOF質譜中產生清晰的訊號。通過模擬測試，質譜數據驗證了本方法在金屬分佈分析中的準確性和可行性。此外，藉由添加PAN基質MALDI-TOF展現出相對定量的能力，對銅離子的檢測極限可達60 μM。
在植物樣品分析中，MALDI-IMS成功檢測到阿拉伯芥根部中的鉛、銅和鎳在分佈情況，實驗結果與先前的文獻報導相符，植物中重金屬主要累積在植物根部組織，業與莖的累積量則較低，證實了本質譜影像法在植物金屬分佈研究中的可靠性。本研究開發的MALDI-IMS平台還能同時檢測植物代謝物分佈，通過與高解析液相層析質譜儀(Liquid chromatography–high resolution mass spectrometry , LC–HRMS)。結果比對，成功鑑定了精氨酸和麩醯胺酸等代謝物的分佈與相對含量，並且MALDI-IMS結果與LC-HRMS相符，證實了該平台在代謝物分析中的準確性和相對定量能力。
總而言之，本研究開發的MALDI-IMS平台為植物金屬和代謝物分析領域提供了一個新的前處理方法。該平台能夠同時獲得植物組織中代謝物與金屬相對含量和空間分佈信息，為深入理解植物的生理過程和環境適應機制提供了新的研究途徑。

This study demonstrates the use of a PAN:CHCA:DHB matrix in MALDI-IMS for visualizing the spatial distribution of both metals and organic compounds in Arabidopsis thaliana seedlings. The method was validated with metal distribution simulation tests and LC-MS.

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