竹筆尖電噴灑質譜技術開發暨研究

Abstract

本研究開發新穎之高靈敏度竹筆尖電噴灑質譜法 (nib-spray/mass spectrometry)，透過被塑型之竹筆尖進行樣品承載與電噴灑游離。竹筆尖可連接到各式電噴灑游離質譜系統。直接使用移液器滴加待測液體到竹筆尖噴嘴上即可逕行分析檢定。竹筆尖噴嘴以開狹縫寬 ~7.5 μm前端閉口當作微儲液槽，此特性可使質譜儀瞬間接收到大量的離子並且防止溶液擴散損失，有助於提高偵測之靈敏度。施予高電壓至竹筆尖噴嘴做電噴灑游離時，樣品迅速的被噴灑進入質譜儀。使用竹筆尖電噴灑游離可迅速的偵測到最大離子層析強度訊號，顯著提高偵測極限。相較於傳統的紙片電噴灑游離質譜法與竹籤電噴灑游離質譜法檢測對-氯安非他命的偵測極限100 ng/mL、50 ng/mL，以竹筆尖電噴灑游離質譜法對於對-氯安非他命偵測極限可達10 ng/mL，本研究將詳細介紹如何使用竹筆尖電噴灑游離、最佳位置、各類狡詐家安非他命檢測與唾液樣品分析。A novel and highly sensitivity electrospray ionization method, nib spray-mass spectrometry (NS-MS), is described. A bamboo pen nib was shaped and used for sample loading and ionization. The nib can be directly connected to ESI ion sources of various mass spectrometers. The sample solution can be loaded onto the nib by normal pipetting. The sample solution slips into the seam (width, ~7.5 µm) of the nib by capillary attraction. Meanwhile, the seam functions as a micro reservoir and prevents the sample solution from spreading to the surface. When a high voltage is applied to the nib, the sample solution is rapidly ejected and ionized toward the mass inlet. Since ionization occurs within a very short period, an abundance of ions is formed, leading to a dramatic improvement in the limit of detection. Using para-chloroamphetamine as a model compound, the limit of detection was determined to be 10 ng/mL. In contrast to this, when the traditional methods were used, including paper-spray and wooden tip-spray, thelimits of detection were 100 and 50 ng/mL, respectively. Detailed information on how to make a bamboo pen nib, the optimized position for ionization, the detection of kinds of designer drugs and its application for the analysis of a saliva sample are also reported.