利用官能化磁性粒子為萃取赭麴毒素A的探針及對掌性色胺酸的分離靜相

Abstract

赭麴毒素A是在麴菌和青黴菌菌種中常見的二次代謝物，然而赭麴毒素A對動物是有毒的。本論文的研究目標之ㄧ為發展赭麴毒素A的偵測方法。由於人類血清蛋白質結構上有兩個部位可與赭麴毒素A雙陰離子具有辨識鍵結作用，因此利用修飾有人類血清蛋白的氧化鐵磁性粒子為親和探針，可在樣品溶液中進行赭麴毒素A萃取濃縮，萃取後可利用外加磁場將磁性粒子從複雜的溶液中分離出來，並經由基質輔助雷射脫附游離質譜法及毛細管電泳-電噴灑游離質譜法進行分析。以基質輔助雷射脫附游離質譜法為分析方法之偵測極限為0.5 μg/L (1.5 mL)。除此之外也開發磁性粒子在毛細管電泳-電噴灑游離質譜法的離線及線上萃取分析系統，在毛細管電泳-電噴灑游離質譜法之偵測極限可達4.0 μg/L (1 mL)。 另外，本論文也利用修飾血清蛋白之磁性粒子為對掌性異構物分離靜相，將磁性粒子注入毛細管中，再藉由外加磁場固定使其成為分離靜相進行毛細管電泳-電噴灑游離質譜法分析，此方法已證明可將DL-色胺酸對掌性異構物在毛細管電泳中進行分離。

Ochratoxin A (OTA), a secondary metabolite generated from either Aspergillus or Penicillium, is toxic for animals. One of the objectives of this dissertation is to develop a method for the analysis of OTA. Human serum albumin (HSA) immobilized Fe3O4 magnetic particles (Fe3O4@HSA) have two binding domains to OTA dianions. On the basis of this feature, HAS immobilized magnetic particles were employed to selectively concentrate OTA from sample solution. The affinity probes-OTA conjugates could be readily isolated from the sample solution after extraction. The results were confirmed by both matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) and capillary electrophoresis electrospray ionization mass spectrometry (CE ESI MS). Furthermore, off-line and on-line extraction using CE ESI MS as the detection method were developed. The results demonstrated that the detection limit of OTA using MALDI MS as the detection method was 0.5 μg/L (1.5 mL), while it was 4.0 μg/L (1 mL) using CE ESI MS as the analysis tool. Additionally, Fe3O4@HSA magnetic particles were employed to be as the chiral stationary phase for DL-tryptophan in CE ESI MS. The Fe3O4@HSA magnetic particles were injected into a capillary and fixed on the capillary by an external magnetic field prior to CE ESI MS analysis. The results demonstrated that this approach was able to separate the chiral DL-tryptophan.