%0 Journal Article
%T Determination of Total Germanium in Chinese Herbal Remedies by Square-Wave Catalytic Adsorptive Cathodic Stripping Voltammetry at an Improved Bismuth Film Electrode
%A Shangwei Zhong
%A Jiali Su
%A Liang Chen
%A Jiefeng Tong
%A Wenfang Jia
%A Xiangjun Li
%A Hong Zou
%J International Journal of Electrochemistry
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/735019
%X A catalytic adsorptive cathodic stripping voltammetric method on an improved bismuth film electrode (BiFE) for the determination of trace germanium in the presence of pyrogallol has been investigated. A well-defined and sensitive stripping peak of Ge(IV)-pyrogallol complex was observed at £¿0.79£¿V (versus SCE) in a 0.1£¿M acetate buffer solution (pH 4.8) at a deposition potential of £¿0.34£¿V. The reduction current is catalytically enhanced by adding KBrO3. The experimental variables and potential interference were studied. Compared with the BiFE plated in the solution prepared based on HAc-NaAc without trisodium citrate, the improved BiFE electrodeposited in the solution of HAc-NaAc containing trisodium citrate displayed a better electroanalytical performance for the determination of germanium(IV). Under the optimized conditions, the detection limit of Ge(IV) was 60£¿ng£¿L£¿1, and the relative standard deviation (RSD) was 3.73% at 5£¿¦Ìg£¿L£¿1 level ( ). This method was successfully applied to determine the total germanium in several Chinese herbal remedies. 1. Introduction Germanium is an essential trace element in human body and very important for our health. Either overaccumulation or deficiency of germanium could result in various diseases, such as acute renal failure [1]. Germanium compounds display a number of biological activities [2] and are described as antioxidants and immunostimulatory medicine that are used to inhibit the progress of cancer and destroy cancer cells [3]. Organogermanium compounds are considered to promote health and cure diseases [4]. Various analytical methods for determining the trace and ultratrace levels of germanium in medicine [4], food [5¨C7], water [8], and soil [5] have been reported, for example, inductively coupled plasma-mass spectrometry (ICP-MS) connected with solid phase extraction [4, 8] and combination of hydride generation [9], graphite furnace atomic absorption spectroscopy (GF AAS) [6, 10], the spectrophotometric method [11], the hydride generation atomic fluorescence spectrometry method [12], the luminol chemiluminescence flow method [13], and electrochemical methods [5, 7, 14¨C16]. Among these methods, electrochemical methods show obvious advantages in accuracy, sensitivity, simplicity, low cost, and analytical speed [7]. Adsorptive stripping voltammetry (AdSV) is well suited to determine the trace metal elements. The AdSV procedures developed for the determination of germanium were based on the adsorptive accumulation of a germanium complex on the hanging mercury drop electrode (HMDE) [5, 14¨C18] or the mercury film
%U http://www.hindawi.com/journals/ijelc/2013/735019/