利用毛細管電泳串聯感應耦合電漿質譜儀

Abstract

摘 要

利用毛細管電泳 (Capillary Electrophoresis) 做為樣品分離之機制、在分析化學中已經廣泛被運用，其優點為相對於氣相層析(Gas-Chromatography)與液相層析 (Liquid Chromatography) 之較高的理論版數，使其於分析時間上有極佳的優勢，常用於生化樣品與一般環境樣品；高解析感應耦合電漿質譜儀 (High-Resolution Inductively Coupled Plasma Mass Spectrometer) ，除具備一般感應耦合電漿質譜儀低偵測極限 (ppb~ppt) 的優點外，因為高解析度的關係，使其更對一般受複合原子干擾之元素，可有效的偵測。 有機錫 (organotin) 普遍地應用於農業及工業上，包括船底防污漆、農藥殺蟲劑與PVC安定劑等，其具有高毒性，而毒性大小因有機取代基之性質和數目而不同。有機錫對生態環境的污染非常嚴重，實有深入研究及探討之必要性。 本實驗室主要是將毛細管電泳與感應耦合電漿質譜儀串聯，首先進行一系列串聯界面的參數探討，並藉由調整輔助溶液擺放之高度和毛細管伸入PEEK管之深度適度地控制吸取效應，以得到最佳之分離效果。接著利用毛細管電泳對於5個三有機錫化合物本身不同之荷質比進行分離，再以感應耦合電漿質譜儀定量，在最佳之串聯界面參數下，以pH 4.6/100 mM醋酸/醋酸銨緩衝溶液、分離電壓20 kV可於6分鐘分離5個三有機錫標準品；遷移時間之相對標準偏差低於1.76%，波峰之積分面積的相對標準偏差低於2.68%，證實實驗方法之再現性良好；而偵測極限則由1.79到9.68 nM。真實樣品部份，嘗試分析南寮漁港之海水中的有機錫化合物。

Abstract

Capillary Electrophoresis (CE) has been widely used in separated chemistry because of its higher number of theoretical plates than Gas Chromatography and Liquid Chromatography. The high-resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) takes advantages than traditional quadrupole ICP-MS in interference free determination of almost the whole periodic table in almost every matrix and lower detection limit (ppt). Some elements are significant interference by polyatomic ions and cannot be tested without using high mass resolution. The CE and HR-ICP-MS are complementary. But how to hyphenated the two instruments finely is critical point of the research. Organotin compounds (OTs) have extensively been used as antifouling agent in ship paints and as fungicides in agriculture and stabilizers in plastic industry over the past years. Speciation is of major interest in OTs analysis, since toxicity is strongly dependent on the species. In order to understand their biological effects and estimate their environmental influences, there is a need for the development and improvement of analytical techniques capable of determining OTs in both aqueous, environmental and biological samples. Our laboratory hyphenated CE and HR-ICP/MS and discussed some parameters of the system. Then, Using the CE to separate the triorganotin compounds, and discussed some analysis parameters, then determined the amounts of tin in HR-ICP-MS for different standards. Five kinds of triorganotin compounds were successfully separated by using a pH 4.6-100 mM acetate buffer within 6 minutes. Reproducibility of migration time and peak area was better than 1.76 and 2.68%, respectively. The limits of detection for various triorganotin compounds were in the range of 1.79-9.68 nM based on peak area. Samples of seawater were analyzed with the CE-ICP/MS combination.