摘要
以铋膜电极为工作电极,采用微分脉冲阳极溶出伏安法直接测定食品样品中痕量铅、镉和锌。在富集电位-1.4V,富集时间180s,铋膜质量浓度150μg·L-1的条件下,铋膜电极对铅、镉和锌的氧化溶出具有良好的电化学响应。铅(Ⅱ)、镉(Ⅱ)和锌(Ⅱ)的质量浓度在5.0~40μg·L-1的范围内与其阳极溶出峰电流呈线性关系,铅(Ⅱ)、镉(Ⅱ)和锌(Ⅱ)的检出限(3S/N)分别为0.80,0.65,0.58μg·L-1。对25μg·L-1铅(Ⅱ)、镉(Ⅱ)和锌(Ⅱ)溶液用铋膜电极连续测定15次,相对标准偏差分别为6.2%,5.1%,7.1%。方法应用于食品中痕量重金属的测定,测定结果与石墨炉原子吸收光谱法的测定值相符。
A bismuth film electrode(BFE)was used as working electrode.Differential pulse anodic stripping voltammetry was applied to the determination of trace amounts of zinc,cadmium,and lead in food samples.Under conditions of enrichment potential of-1.4 V,enrichment time of 180 s,and bismuth film concentration of150μg·L-1,BFE exhibited good electrochemical response to oxidation and stripping of zinc,cadmium,and lead.Linear relationships between anodic stripping peak current and mass concentration of zinc(Ⅱ),cadmium(Ⅱ),and lead(Ⅱ)were in the same range of 5.0-40μg·L-1,with detection limits(3S/N)of 0.80,0.65,0.58μg·L-1for zinc(Ⅱ),cadmium(Ⅱ),and lead(Ⅱ)respectively.Precision of the method was tested at concentrations of25μg·L-1 zinc(Ⅱ),cadmium(Ⅱ),and lead(Ⅱ)solution for 15 duplicates with BFE,values of RSD were 6.2%,5.1%,and 7.1%,respectively.The proposed method was applied to the determination of trace heavy metals in food,giving results in agreement with values obtained by GFAAS method.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2015年第3期386-389,共4页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
浙江省公益性技术应用研究计划项目(2012C37073)
宁波市自然科学基金(2011A610089)
