Mn-CCA-CPC浊点萃取火焰原子吸收法测定水环境中锰

使用浊点萃取的方法分离富集水环境中痕量的锰离子，创新性地使用钙羧酸(CCA)与阳离子表面活性剂氯代十六烷基吡啶(CPC)为络合剂与锰离子形成更稳定的三元络合物，以TritonX-114为萃取剂浊点萃取分离富集水环境中的痕量锰，同时采用火焰原子吸收法进行测定，建立了测定水环境中痕量锰的新方法。对影响浊点萃取的主要因素如pH、TritonX-114的用量、CCA用量、CPC用量、NaCl用量、共存离子影响、加热温度、加热时间、离心时间、冰浴时间进行了优化。在优化的实验条件下，Mn2+-CCA-CPC体系分离富集锰有很好地效果，能够很好的克服基体干扰，浊点萃取体系在锰含量0.3～1.5 mg·L-1时呈现良好的线性关系。方法的灵敏度为1.939 mg·L-1，精密度为0.39%，检出限为(3σ)0.27 μg·L-1。测定自来水与井水中的锰含量的结果为33.5和64.5 μg·L-1，同时做加标回收实验，回收率在99.1%～101.5%之间。符合国际标准，因此该方法能够成功应用到水环境中的锰含量的测定，结果令人满意。

Determination of Manganese in Water Samples by Cloud Point Extraction with MN-CCA-CPC Flame Atomic Absorption Spectrometry

In this work, a simple and novel cloud point extraction (CPE) method for the separation and preconcentration of manganese in aquatic environment was developed and combined with flame atomic absorption spectrometry (FAAS). Manganese was formed a complex with Calcon carboxylic acid (CCA) in the presence of Cetyl pyridinium chloride (CPC) and Triton X-114. The main factors affected the CPE, such as pH, the dosage of Triton X-114, CCA, CPC, NaCl, coexisting ions, and the heating time and heating temperature. After optimization of the experimental conditions, the system of Mn-CCA-CPC was able to overcome the matrix interference and showed the significant effect of separation of enrichment. The precision of the method was 0.39% and the limit of detection was 0.27 μg·L-1 of Mn. The results of the determination of manganese content in tap water and groundwater were 33.5 and 64.5 μg·L-1, which was in line with the international standards, so the method can be successfully applied for the determination of manganese in the water environment.