[Microchip capillary electrophoresis-electrochemical detection of nitrite using a modified carbon paste electrode].
Carbon paste electrode modified with 3-mercaptopropyltrimethoxysilane copper (MPTMS-Cu) encapsulated in molecular sieve MCM-41 was prepared. The electrocatalytic behavior of the modified electrode towards the reduction of nitrite was studied in detail, including pH-dependence and composition-dependence studies. A microchip capillary electrophoresis-electrochemical detection system with the modified carbon paste as electrode was fabricated. The application of the system for the detection of nitrite is discussed. The detection was finished within 40 s under the following conditions: 50 mmol/L sodium acetate buffer at pH 5.8, -1.6 kV running voltage. The peak current was linear with the concentration of nitrite over 10.0 micromol/L-5.0 mmol/L and the detection limit was 4.0 micromol/L in pure water.
Wei
Peihai
P
Lanzhou Institute of Chemical Physics, The Chinese Academy of Sciences, Lanzhou 730000, China.
Li
Guanbin
G
Chen
Liren
L
D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D019075:Electrophoresis, Capillary / Q000379:methods; D046209:Electrophoresis, Microchip / Q000379:methods*; D009573:Nitrites / Q000032:analysis*
D009573:Nitrites; D002244:Carbon