氧化铝掺杂碳糊电极对浆果中铅的快速检测及其干扰分析

Rapid determination and interference analysis of lead in berries by alumina doped carbon paste electrode

中文关键词:  铅  浆果  电化学  快速检测  干扰

英文关键词:lead  berry  electrochemistry  rapid detection  interference

中文摘要:

      目的 开发氧化铝掺杂碳糊电极测定浆果中铅(Pb)的电化学快速检测方法。方法 以浆果为研究对象, 采用制备的氧化铝掺杂修饰碳糊电极(alumina doped carbon paste electrode, Al2O3-CPE), 以方波阳极溶出伏安法(square wave anodic stripping voltammetry, SWASV)检测其中的Pb(II)。分析电极的检测性能, 优化电解液组成, 确定检测条件。通过比较匀浆/超声提取和湿法消解两种前处理, 确定适宜浆果中Pb快速检测的前处理方法; 并对浆果基质中主要干扰因素进行分析。结果 采用M醋酸:M醋酸钠=1.05的电解液, 建立的SWASV检测Pb(II)的线性范围为0.5~80.0 μg/L, r2=0.9976。匀浆/超声提取-SWASV检测结果可达到湿法消解-电感耦合等离子体质谱法(inductively coupled plasma-mass spectrometry, ICP-MS)的95.05%~106.11%。K(I)、Ca(II)、Mg(II)和花青素对Pb(II)检测影响小; Zn(II)、Fe(II)和Fe(III)降低了Pb(II)的检测响应; 而柠檬酸则相反, 呈现增强效应; 样品提取稀释200倍后, 各干扰因素对Pb(II)检测干扰均小于5%。5种浆果中均检出Pb, SWASV法检测含量为0.068~0.112 mg/kg, 其中圣女果中Pb含量高于其他浆果。结论 本研究结果对果蔬中Pb的电化学快速检测具有指导意义, 为开发低成本、易操作的植物性食品中重金属快速检测方法提供技术参考。

英文摘要:

      Objective To develop an electrochemical rapid detection method for the determination of lead (Pb) in berries by alumina doped carbon paste electrodes. Methods Berries were taken as research objects, and a prepared alumina doped carbon paste electrode (Al2O3-CPE) was used to determine Pb(II) in the samples though square wave anodic stripping voltammetry (SWASV). The detection performance of the electrode was analyzed. Electrolyte composition was optimized to determine the detection conditions. The suitable pre-treatment for rapid measurement was gained though comparation of homogenate-ultrasonic extraction and wet digestion. And the main interferences of berries matrix were analyzed. Results The results showed that when using the electrolyte solution with Macetic acid:Msodium acetate=1.05, the linear range of the established SWASV for Pb(II) detection was 0.5?80.0 μg/L, r2=0.9976. In verification test, detection results of the homogenate-ultrasonic extraction-SWASV reached 95.05%?106.11% of wet digestion-inductively coupled plasma mass spectrometry (ICP-MS) detection results. After homogenate-ultrasonic treatment as samples, K(I), Ca(II), Mg(II) and anthocyanins had little influence on Pb(II) detection. Zn(II) and Fe(II) strong inhibited the detection response, and citric acid showed amplification effect oppositely. And the signal deviation could be controlled within 5% when matrix was diluted 200 times in the detection. Pb was detected from all 5 kinds of berries with the content was 0.068?0.112 mg/kg detected by SWASV method. The content of Pb in cherry tomato was higher than other berries. Conclusion The results of this study have guiding significance for the electrochemical rapid detection of Pb in fruits and vegetables, and provide technical reference for the development of low-cost and easy to operate methods for the rapid detection of heavy metals in plant-based foods.