化粧品中局部麻醉劑成分檢驗方法之建立

Determination of Local Anesthetics in Cosmetics by Liquid Chromatography - Tandem Mass Spectrometry

本研究利用超高效液相層析串聯質譜法（ultra - performance liquid chromatography-tandem-mass spectrometry, UPLC/MS/MS）建立一簡單、快速可同時分析化粧品中benzocaine、cocaine、dibucaine、lidocaine、procaine及tetracaine等6種局部麻醉劑之檢驗方法。檢體以10 mM甲酸銨之50%甲醇溶液溶解並定容後，經Waters AQUITYUPLC BEH層析管柱（2.1 × 150 mm, 1.7 μm），採用10 mM甲酸銨溶液及甲醇/乙腈（4:1,v/v）溶液為移動相作梯度沖提，並以電灑游離法（ESI）搭配多重反應偵測模式（multiplereaction monitoring, MRM）偵測，6種成分之標準曲線線性範圍為5 - 25 ng/mL，線性迴歸係數r^2皆為0.995以上，同日內及異日間之相對標準偏差均小於9.1%，添加回收試驗之回收率介於85.3 - 118.5%，相對標準偏差皆小於12.5%，定量極限皆可達1.25μg/g，本方法將公開供各界參考引用。

A simple and rapid method was developed for the quantification of 6 local anesthetics, namely benzocaine, cocaine, dibucaine, lidocaine, procaine and tetracaine in cosmetics. The anesthetics in the samples were extracted by 50% methanol containing 10 mM ammonium formate and then analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS) with an electrospray ionization (ESI) interface. The LC separation was performed using a Waters AQUITY UPLC BEH C-18 column (2.1 × 150 mm, 1.7 μm) and gradient elution with a mobile phase consisting of 10 mM ammonium formate solution and methanol/acetonitrile solution (4:1, v/v). The linear concentrations of the 6 local anesthetic solutions were in the range of 5.0 - 25 ng/mL with r^2 values greater than 0.995. Intraday and inter-day standard deviations were all below 9.1%. The recoveries of triplicate tests in different concentrations were in the range of 85.3 - 118.5% with relative standard deviations of less than 12.45%. A quantification limit of 1.25 mg/g was achieved.