液相層析質譜術在藥物分析之應用   全文下載

Liquid Chromatography-Mass Spectrometry in Drug Analysis

大氣壓下離子化法是液相層析質譜術近來最重要的發展，本文介紹電灑法（ESI）及大氣壓化學游離法（APCI）兩種大氣壓離子化法的基本原理與特性。電灑法離子化的過程在溶液中進行，樣品在離子化前不需先受熱揮發成氣態分子，適合高極性及熱不穩定的樣品。電灑法一般較佳的流速範圍在40-200μ L／min，流速上限為1mL／min。大氣壓化學游離法和利用流動相成分及大氣中的水氣做為化學離子化的試劑氣體，適合低極性到中極性的樣品。大氣壓化學游離法可接受比電灑法更高的流速，可配合傳統4.6mm ID的填充管柱（1-2mL／min）而不需分流。最後我們以兩個實例來說明液相層析大氣壓下離子化質譜術在藥物分析上應用的潛力。

Atmospheric ionization is the most important development for LC/MS in recent years. Two atmospheric pressure ionization methods, electrospray ionization(ESI) and atmospheric pressure chemical ionization (APCI) are described. Electrospray is most suited to compounds of high polarity or thermolabile because ionization of electrospray is performed in solution, and vaporization of analyte before ionization is not necessary. The optimal flow rate of electrospray, in general, is in the range of 40-200 ul/min, although the upper limit is about I mL/min. Atmospheric pressure chemical ionization utilizes the constituent of mobile phase and water vapor as the reagent gas for chemical ionization. This method is best suited for compounds of low to medium polarity. APCI can take higher flow rate than ESI and it can directly couple with conventional 4.6mmID packed column (1-2 mL/min) without splitting. Two examples are used to illustrate the potential of using LC-API/MS system in drug analysis.