Abstract A novel preconcentration method based on the magnetic chitosan hydrogels (MCH) was developed for trace level determination of cadmium in sorrel (Rumex acetosella) and rocket (Eruca sativa) as edible plants. Magnetic Fe3O4@chitosan composites were synthesized, characterized and used to obtain lower detection limits for cadmium by slotted quartz tube (SQT) - atomic absorption spectrophotometry (FAAS). The Box Behnken multivariate design was used to optimize the experimental variables. Under the optimum conditions, developed method provided 97.5 fold enhancements in detection power when compared to conventional FAAS. Proposed method also provided low detection and quantification limits (0.20 and 0.68 ng/mL, respectively), high precision with %RSD of 5.3 and high accuracy with recoveries ranged from 96.0–110.4% for Rumex acetosella and Eruca sativa matrices, respectively. The results demonstrated that magnetic chitosan hydrogels could be promising materials to be used as sorbent material in solid phase microextraction yielding simple, cost-effective and environmentally friendly preconcentration process.

中文翻译：

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一种测定酢浆草和火箭植物中超痕量镉的新分析方法：基于磁性壳聚糖水凝胶的固相微萃取-开槽石英管-火焰原子吸收分光光度法

摘要 开发了一种基于磁性壳聚糖水凝胶 (MCH) 的新型预浓缩方法，用于测定可食用植物酢浆草 (Rumex acetosella) 和芝麻菜 (Eruca sativa) 中的痕量镉。磁性 Fe3O4@壳聚糖复合材料被合成、表征并用于通过开槽石英管 (SQT) - 原子吸收分光光度法 (FAAS) 获得较低的镉检测限。Box Behnken 多元设计用于优化实验变量。在最佳条件下，与传统 FAAS 相比，开发的方法提供了 97.5 倍的检测能力增强。提议的方法还提供低检测限和定量限（分别为 0.20 和 0.68 ng/mL）、高精度，%RSD 为 5.3，准确度高，回收率范围为 96.0–110。Rumex acetosella 和 Eruca sativa 基质分别为 4%。结果表明，磁性壳聚糖水凝胶是一种很有前途的材料，可用作固相微萃取中的吸附剂材料，产生简单、经济且环保的预浓缩过程。