Sample stacking and sweeping in microemulsion electrokinetic chromatography under pH-suppressed electroosmotic flow.
Two on-line sample concentration techniques, sample stacking and sweeping under pH-suppressed electroosmotic flow, were evaluated in microemulsion electrokinetic chromatography. The concept of stacking with anion selective electrokinetic injection and a water plug in a reverse-migrating microemulsion (SASIW-RMME) was brought forward in this article. Six flavonoids were concentrated using a microemulsion consisting of 80 mM sodium dodecyl sulfate, 1.2% (v/v) ethyl acetate, 0.6% (v/v) 1-butanol, 10% acetonitrile (v/v) and 50 mM phosphoric acid (pH* 1.8). Significant detector response improvements were achieved. The limits of detection were in the low ng/ml level. Finally, the sample of Fructus aurantii Immaturus was analyzed using sweeping technique.
Zhu
Jinhua
J
State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, China.
Qi
Shengda
S
Zhang
Huige
H
Chen
Xingguo
X
Hu
Zhide
Z
D000465:Algorithms; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D053841:Electroosmosis; D004655:Emulsions; D005419:Flavonoids / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D012996:Solutions
D004655:Emulsions; D005419:Flavonoids; D007202:Indicators and Reagents; D012996:Solutions