Unequal Electric Field Assisted Sweeping-MEKC for the Determination of Dopamine and Norepinephrine in Urine by Violet Light Emitting Diode-Induced Fluorescence Detection

• Main Authors: Yen-Cheng Li, 李晏誠
• Other Authors: Cheng-Huang Lin
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/02139311281928778502

碩士 === 國立臺灣師範大學 === 化學系 === 93 === An unequal electric field assisted sweeping-MEKC (UEFA/sweeping-MEKC) technique is proposed, for the first time, and compared to the normal sweeping-MEKC with reference to sensitivity and separation efficiency. NDA (naphthalene-2,3-dicarboxaldehyde) derivatized-dopamine and -norepinephrine, were selected for use as model compounds. In the case of normal sweeping-MEKC, the findings show that, when a portion (30 cm, ~1/3 of the total length of the capillary) of sample matrix was injected into the capillary, the separation resolution was only 1.5. However, this was dramatically improved to 9.2 when the UEFA/sweeping-MEKC technique was applied. In the view of sensitivity, when a violet-LED (~ 2mW) was used as the fluorescence excitation source, the limit of detection for NDA-labeled dopamine was determined to ~10-9 M, the similar to that for normal sweeping-MEKC, since the injected sample volume is same. In addition, this method also provides sufficient sensitivity and separation efficiency for the detection of low concentrations of dopamine in urine.