Determination of magnesium in foods by single-sweep polarography.
In KOH, the Mg(II)-bromopyrogallol red (BPR) complex produced a very sensitive polarographic wave at -1.30 V. The wave height was linear with the concentration of Mg(II) in the range of 0.05 to 2 microg/mL. The detection limit was 0.01 microg/mL. The electrochemical behavior of Mg(II)-BPR was studied by electrochemical and spectrophotometric methods. Experiments proved that the polarographic wave of Mg(II)-BPR was due to the reduction of BPR in the Mg(II)-BPR complex. The method, which was sensitive, selective, and simple to perform, was used to determine magnesium in foods, and the results were consistent with those obtained by atomic absorption spectroscopy.
Xiangchun
Zhou
Z
Yangtze University, College of Chemistry and Environmental Engineering, Jingzhou, 434023, People's Republic of China.
Lirong
Wang
W
Yan
Zeng
Z
Guanghan
Lu
L
Peng
Zhen
Z
D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004396:Coloring Agents / Q000494:pharmacology; D004563:Electrochemistry / Q000379:methods*; D005504:Food Analysis / Q000379:methods*; D006878:Hydroxides / Q000032:analysis*; D008274:Magnesium / Q000032:analysis* / Q000302:isolation & purification; D017616:Magnesium Compounds / Q000032:analysis / Q000302:isolation & purification; D011048:Polarography / Q000379:methods*; D017680:Potassium Compounds / Q000032:analysis*; D011748:Pyrogallol / Q000032:analysis*; D015203:Reproducibility of Results; D013054:Spectrophotometry, Atomic / Q000379:methods
D004396:Coloring Agents; D006878:Hydroxides; D017616:Magnesium Compounds; D017680:Potassium Compounds; C109304:bromopyrogal red; D011748:Pyrogallol; D008274:Magnesium; C029943:potassium hydroxide