3D列印溶液槽鑲嵌毛筆尖電噴灑/質譜法的開發與研究

Abstract

本研究基於紙片電噴灑（paper-spray）的原理，首度開發毛筆尖電噴灑技術，並以3D印表機印製可鑲嵌毛筆尖之溶液容槽，不僅可以穩定電噴灑現象，並可提供長時間質譜測量之用。這是利用棉線的毛細現象，將揮發性溶劑輸送至毛筆尖端處。在筆尖處施加高電壓，即可進行電噴灑。有別於傳統紙片電噴灑中使用的三角形濾紙，筆的尖端比三角形濾紙更尖銳，電噴灑效果更好。此外，毛筆尖不僅具有製作簡單、操作容易、可以長期使用、清洗方便等多項優點，而且設計新穎、便於攜帶、對於現場即時採樣（包括液體、粉末或固體表面等）也非常方便。3D樣品溶液槽是選用耐酸鹼材料的ABS樹脂（丙烯腈-丁二烯-苯乙烯共聚物）。溶液槽重量不及1克，製作成本也低於一百元。溶劑容槽的體積為1 mL，可連續滋潤筆尖約3小時以上。實驗發現，選用尼龍毛筆裁製的電噴灑筆尖的效果最好。推測其原因可能是尼龍纖維表面較平整光滑，可使樣品快速噴灑並離子化，使質譜儀瞬間可以接收到較多量的離子，有助於提高偵測的靈敏度。以亞甲基藍為測試樣品，偵測靈敏度可達2 ppb。同質譜條件之下，靈敏度較三角濾紙高出一個數量級以上。對於尿液及唾液檢體中藥物的檢測，皆可快速且準確的偵測出樣品的分子量。

A novel type of electro-spray ionization technique for mass spectrometer measurement was developed by using a writing brush which can be loaded on a 3D-printed plastic cell. It can not only stabilize the spray phenomenon but also provide to the long time mass spectrometer measurement. The cotton can transfer the volatile solvent to the brush tip by capillary phenomenon. Electrically spraying can be done by applying high voltage at the brush tip. The result of this electro-spray method is better than traditional chromatography paper in PS-MS because the brush tip is sharper than triangle chromatography paper. The advantages of the device are simple, easy to operate, long-term use and easy to clean. The model of 3D cell is produce by using ABS (Acrylonitrile Butadiene Styrene) which is acid alkali resistant as material. The weight of cell is less than 1 gram and its cost is under 100 NT dollars. The volume of cell is 1 mL. The brush tip can be soaked in the cell over 3 hours. The experiment result showed that choosing nylon as the brush works best. The most possible reason might be that nylon fiber surface is smooth, which make sample can spray faster. Therefore, mass spectrometer can receive a relatively large amount of ions. It may increase the sensitivity of detection. The detection of Methylene blue is 2 ppb. The sensitivity is one order higher than triangle chromatography paper. It can quickly and accurately detect the molecular weight of drugs in urine and saliva.