Determination of oxalic acid in spinach with carbon nanotubes-modified electrode
Yanqiong Zheng, Changzhu Yang, Wenhong Pu and Jingdong Zhang
Food Chemistry, Volume 114, Issue 4, 15 June 2009, Pages 1523-1528
2009
บทคัดย่อ
This work investigated the electrocatalytic oxidation of oxalic acid on multiwall carbon nanotubes (MWNTs) modified glassy carbon (GC) electrode. The result indicated that the oxidation of oxalic acid was greatly improved at the MWNTs-modified GC (MWNTs/GC) electrode as compared with the bare GC electrode. The effects of the MWNTs suspension amount, pH and scan rate on the electrooxidation response of oxalic acid were studied by voltammetry. The surface concentration and diffusion coefficient (DR) of oxalic acid at the MWNTs/GC electrode were determined by chronocoulometry. This MWNTs/GC electrode presented a wide linear response ranging from 5.0 × 10-5 to 1.5 × 10-2 Mfor oxalic acid. The detection limit (S/N = 3) was estimated to be 1.2 × 10-5 MBased on this MWNTs/GC electrode, the content of oxalic acid in spinach was successfully determined.