Citation: Chen Rongli , Wang Lizeng , Liu Ping , Lu Maosun , Yin Peiyu . Determination of Maleic Acid in Fumaric Acid by Third Derivative Convoluted Polarographic Wave. Chinese Journal of Analytical Chemistry, 1991, 19(6): 673-676. [复制]
Determination of Maleic Acid in Fumaric Acid by Third Derivative Convoluted Polarographic Wave
A method to determine micro amount of meleic acid in fumaric acid is described, and the results confirmed by gas chromatography. In a supporting electrolyte solution containing 8% alcohol,0.2 mol/L NH3/NH4Cl(pH=6),the peak potential of maleic acid appears at -1.36V (vs.SCE). The peak height is directly proportional to the concentration of maleic acid over a range of 0.07～50μg/ml. The concentration ratio of maleic acid to fumaric acid may be allowed up to 1:250.The relative standard deviation is 1.1% for twenty replicate determinations. The recovery is in the range of 96～103%. The electrode process is presented as follows: 1. in acid medium HOOC-CH=CH-COOH+2H++2e→HOOC-CH2-CH2-COOH; 2. at pH=6 -OOC-CH=CH-COOH+2H++2e→-OOC-CH2-CH2-COOH.