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Electroanalysis of tert ‐Butylhydroquinone in Edible Oil at a Nafion‐Coated Probe
Author(s) -
Surareungchai Werasak,
Kasiwat Duangsuda
Publication year - 2000
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/1521-4109(200010)12:14<1124::aid-elan1124>3.0.co;2-m
Subject(s) - propyl gallate , detection limit , chemistry , differential pulse voltammetry , butylated hydroxyanisole , sunflower oil , nafion , chromatography , soybean oil , nuclear chemistry , electrochemistry , electrode , antioxidant , cyclic voltammetry , organic chemistry , food science
An electrochemical probe consisting of co‐planar platinum working and counter electrodes, and a silver quasi‐reference electrode, was coated with a film of ionically conducting polymer, Nafion. The electrochemical behavior of ferrocene in a cooking oil could be observed at the probe without sample pretreatment. Hence it was demonstrated that the probe could be used to perform direct analysis of the antioxidant tert ‐butylhydroquinone (TBHQ) in edible oils. Using differential pulse voltammetry (DPV), a linear response to TBHQ was obtained across the concentration range 1–50 mg kg –1 , with a sensitivity of 6.49×10 –11 A kg mg –1 ; the detection time being 2 min for each assay. The limit of detection was 0.25 mg kg –1 (S/N=3). Interference from phenolic antioxidants such as tert ‐butylhydroxyanisole (BHA), tert ‐butylhydroxytoluene (BHT), propylene glycol, and propyl gallate was studied. BHA showed some interference at TBHQ:BHA ratios of 1:1 and 1:2. The others did not interfere. The mean recoveries of TBHQ spiked into samples of soybean, sunflower and palm oil were found to be 96%, 102% and 102%, respectively ( n =5).