Jones J W, Gajan R J, Boyer K W, Fiorino J A
J Assoc Off Anal Chem. 1977 Jul;60(4):826-32.
An analytical method is presented for determining cadmium, copper, and lead by differential pulse anodic stripping voltammetry and zinc by cathodic scan differential pulse voltammetry. Food samples are dry ashed using a sulfuric acid ashing aid, dissolved in dilute nitric acid, buffered at pH approximately 4.3 with an acetate buffer, and quantitatively analyzed using the technique of standard additions at a hanging mercury drop electrode. The quantitation limits (5 times the estimated detection limits) are approximately 5 ng/g for Cd, Cu, and Pb, and 50 ng/g for Zn. Accuracy of the method is established by (a) analysis of NBS Standard Reference Material No. 1577 Bovine Liver, (b) comparison of results obtained by the method described with those obtained by independent analytical methods, and (c) quantitative recovery of analyte metals from fortified, noncanned food samples. Results from an interlaboratory method trial indicate that the method is suitable for the analysis of a variety of food types.
本文介绍了一种分析方法，通过差分脉冲阳极溶出伏安法测定镉、铜和铅，通过阴极扫描差分脉冲伏安法测定锌。食品样品用硫酸作为灰化助剂进行干灰化，溶解在稀硝酸中，用乙酸盐缓冲液在约pH 4.3下进行缓冲，并在悬汞滴电极上采用标准加入法进行定量分析。镉、铜和铅的定量限（估计检测限的5倍）约为5 ng/g，锌的定量限为50 ng/g。该方法的准确性通过以下方式确定：(a)分析NBS标准参考物质1577号牛肝；(b)将所述方法获得的结果与独立分析方法获得的结果进行比较；(c)从强化的非罐装食品样品中定量回收分析物金属。实验室间方法试验的结果表明，该方法适用于分析多种食品类型。
