Nafion membrane electrophoresis with direct and simplified end-column pulse electrochemical detection of amino acids.
A novel electrophoresis technique, in which the separation column was replaced by a strip of Nafion membrane (5.0 cm x 0.20 mm x 0.25 mm), was developed for the separation of an amino acid mixture (glycine, asparic acid and lysine), followed by quadruple-pulse electrochemical detection. Nafion membrane contains hydrophilic pores (10-20 A and 50-60 A in size) acting as very narrow electrophoresis channels. The fixed-charge sites (-SO(3) (-)) on the hydrophilic pore surface provide a strong charged background. A platinum disk electrode (0.90 mm inner diameter) was employed as the detection electrode and the electrophoresis cathode was used as the quasi-reference and counter electrode for the end-column electrochemical detector, without decoupler. Under optimized conditions the mixture of amino acids could be separated at a voltage of only 90 V with a detection limit of 10(-7) M, indicating that Nafion membrane electrophoresis is a potentially attractive technique for the separation of small organic molecules or ions.
Fang
Cheng
C
Department of Chemistry, Wuhan University, Wuhan, P R China. fangc@chem.whu.edu.cn
Wu
Bingliang
B
Zhou
Xingyao
X
D000596:Amino Acids / Q000302:isolation & purification*; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005465:Fluorocarbon Polymers; D008567:Membranes, Artificial; D012996:Solutions
D000596:Amino Acids; D005465:Fluorocarbon Polymers; D008567:Membranes, Artificial; D012996:Solutions; C040402:perfluorosulfonic acid