Determination of metals in fish and shrimp (Farfantepenaeus paulensis) from Patos Lagoon (Pelotas- RS, Brazil) by MIP OES

Abstract In the present work, the microwave induced plasma optical emission spectrometry technique was employed to determine the concentrations of Al, Cd, Cu, Hg, Mg, Sb and Zn in fish samples (catfish, mullet, wolf fish, spotted sorubim and croaker) and Al, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sb, Ti and Zn in shrimp (Farfantepenaeus paulensis) samples. Samples were prepared by acid decomposition with reflux system. For fish analysis, two systems of sample introduction into plasma were compared: conventional nebulization and multimode system. In order to get the best conditions using the multimode system, parameters such as the concentrations of HCl and of reducing agent NaBH4 were investigated. The method accuracy was assessed through analysis of certified reference materials and analyte addition tests. The obtained recoveries were satisfactory for both samples. For fish, the best results were obtained using the multimode system and the maximum concentrations (in mg·kg-1) were: 6.43 to 24.7 for Al; 0.41 to 6.6 for Cu; 168.2 to 211.2 for Mg and 23.1 for Zn. For shrimp samples, the maximum concentrations (in mg·kg -1) were: 92.1 for Al; 1,070 for Ca; 4.57 for Cu; 87.9 for Fe; 451 for Mg; 8.9 for Mn and 29.2 for Zn. All concentrations found for Cd, Cu, Pb and Zn are within the limits permitted by the current legislation in Brazil for fish. The results showed the suitability of the present method using MIP OES technique for multielemental determination in fish and shrimp samples.

摘要 本研究采用微波诱导等离子体光发射光谱法（Microwave Induced Plasma Optical Emission Spectrometry，简称MIP OES），对鱼类样本（鲶鱼、鲻鱼、狼鱼、斑点苏鲁比姆鱼、石首鱼）中的铝（Al）、镉（Cd）、铜（Cu）、汞（Hg）、镁（Mg）、锑（Sb）、锌（Zn），以及虾样本（圣保罗仿对虾，Farfantepenaeus paulensis）中的铝（Al）、钡（Ba）、钙（Ca）、镉（Cd）、铬（Cr）、铜（Cu）、铁（Fe）、镁（Mg）、锰（Mn）、镍（Ni）、铅（Pb）、锑（Sb）、钛（Ti）、锌（Zn）的浓度开展了定量测定。样本采用回流酸分解法完成前处理。针对鱼类样本的分析，本研究对比了两种等离子体进样方案：常规雾化进样系统与多模式进样系统。为优化多模式进样系统的最佳工作参数，本研究考察了盐酸（HCl）与还原剂硼氢化钠（NaBH4）的浓度等关键条件。通过有证参考物质分析与加标回收实验对方法的准确度进行了评价，两类样本的加标回收率均令人满意。采用多模式进样系统时鱼类样本的分析效果最优，各元素的最大浓度（单位：mg·kg⁻¹）如下：铝6.43~24.7、铜0.41~6.6、镁168.2~211.2、锌23.1。虾样本的各元素最大浓度（单位：mg·kg⁻¹）如下：铝92.1、钙1070、铜4.57、铁87.9、镁451、锰8.9、锌29.2。本次检测得到的镉、铜、铅与锌浓度均符合巴西现行鱼类食品相关法律法规的限量标准。实验结果表明，本研究所采用的微波诱导等离子体光发射光谱法（MIP OES）可适用于鱼类与虾样本的多元素定量分析。