|Development of integrated devices with stirring-based solid phase microextraction and chromogenic capability for the enrichment and determination of heavy metal ions by smartphones
|Place of Conferral
|重金属离子 Heavy metal ions 比色法 colorimetry 3D打印 3D printing 固相微萃取 solid-phase microextraction 智能手机检测 smartphone detection
第三章：用所研制的搅拌式固相微萃取显色一体化智能手机检测装置对重金属离子Zn2+、Pb2+进行萃取富集与检测，并对固相微萃取条件进行了考察，确定了Zn2+和Pb2+萃取的适宜条件。Zn2+萃取的条件为：乙酸-乙酸钠缓冲体系，pH为5.0，离子强度调节介质为5 M NaCl，转速为200 r·min-1，显色剂用量为5.0 μL，温度为45 ℃，搅拌时间为10 min，至吸附平衡的时间为10 min。Pb2+萃取的条件为：柠檬酸铵-盐酸-氢氧化钠体系，pH为7.5，离子强度调节介质为20%的KNO3，转速为200 r·min-1，显色剂用量为5.0 μL，温度为40 ℃，搅拌时间为10 min，至吸附平衡的时间为10 min。
第四章：在选定的实验条件下对所建立方法性能进行评估，并用于实际样品测定。发现在0.03~0.30 μg·mL-1范围内，Zn2+浓度与R通道变化值△R呈现良好的线性关系，△R为R通道富集前后的变化值，检出限为0.011 μg·mL-1。在0.03~0.30 μg·mL-1范围内，Pb2+浓度与B通道变化值△B呈现良好的线性关系，△B为B通道富集前后的变化值，检出限为0.010 μg·mL-1。对Zn2+、Pb2+检测选择性进行了测试，测定了污水、土壤、水草和中药材四种实际样品中Zn2+、Pb2+的含量。采用等离子体发射光谱法（ICP-AES）对所研制装置和所建立方法的准确性进行了评估，结果证明所研制设备的结果与ICP-AES结果没有显著性差异。
With the continuous advancement of industrialization, the environment pollution caused by the release of huge amounts of heavy metals has posed a serious threat to the normal growth of plants and human health. Timely and accurate detection of heavy metals in the environment is an essential step to prevent their pollution. There are many techniques available for the detection of heavy metal ions, including optical and electrochemical methods, but they usually require complex operations, sophisticated instruments and skilled operators. Therefore, there is an urgent need to develop portable, low-cost, easy-to-use detection systems for the detection of heavy metal ions in the environment. In this dissertation, we have developed a original device that incorporated stirring based solid phase microextraction with in-membrane simultaneous chromogenic capability for the enrichment and determination of heavy metal ions with 3D printed accessories. A smartphone is employed to image the color of the membrane on the specifically designed stirring bars as the analytical signals. The device has the potential of on-site rapid detection and it has been used for the detection of trace amounts of Zn2+ and Pb2+ in real samples.
The dissertation contains four chapters:
Chapter 1, the commonly used detection methods for heavy metal ions are introduced, and the colorimetric detection methods are reviewed. The classification and application of smartphone based sensing, 3D printing technology, and the coating materials for the extraction are also briefly summarized.
Chapter 2, a stirring based solid phase microextraction with in-membrane simultaneous chromogenic capability for the enrichment and determination of heavy metal ions using the smartphone was constructed. In the work, the effect of different colors of polylactic acid stirring devices on the extraction of heavy metal ions was investigated, and the structure of the stirring solid phase microextraction color integration device was selected. The smartphone imaging device was designed and the position of the LED lamp as the light source was determined. The parameters of the smartphone camera for the detection were examined, they were: white balance (WB) is daylight, light sensitivity (ISO) is 800, and shutter speed (S) is 1/2000 s for the highest signal-to-noise ratio.
Chapter 3, the constructed detection device was used for the extraction, enrichment and detection of heavy metal ions Zn2+ and Pb2+. The conditions for Zn2+ solid phase microextraction were as follows: acetic acid-sodium acetate buffer system, pH was 5.0, ionic strength adjusted with 5 M NaCl, stirring rate was 200 r·min-1, dithizone volume was 5.0 μL, temperature was 45 °C, stirring time was 10 min, adsorption equilibrium time was 10 min. The conditions for Pb2+ solid phase microextraction were as follows: ammonium citrate-hydrochloric acid-sodium hydroxide system, pH was 7.5, ionic strength adjusted with 20% KNO3, stirring rate was 200 r·min-1, dithizone volume was 5.0 μL, temperature was 40 °C, stirring time was 10 min, and adsorption equilibrium time was 10 min.
Chapter 4, the performance of the established method was evaluated under chosen conditions. It was found that in the range of 0.03~0.30 μg·mL-1, the Zn2+ concentration showed a good linear relationship with the change of R channel value △R, which was obtained after and before the enrichment. The limit of the detection (LOD) was 0.011 μg·mL-1. In the range of 0.03~0.30 μg·mL-1, the Pb2+ concentration showed a good linear relationship with the change of B channel value △B. The LOD was 0.010 μg·mL-1. The selectivity of Zn2+ and Pb2+ detection was also evaluated and the contents of Zn2+ and Pb2+ in sewage, soil, aquatic plants and herb samples were determined. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used to verify the accuracy of the constructed device and the established method, and the results obtained are not significant difference with the results obtained by the constructed device.
|MOST Discipline Catalogue
|理学 - 化学 - 分析化学
|杨梅. 用于重金属离子富集的搅拌式固相微萃取显色一体化智能手机检测装置研制[D]. 兰州. 兰州大学,2023.
|Files in This Item:
|There are no files associated with this item.
|Recommend this item
|Export to Endnote
|Similar articles in Google Scholar
|Similar articles in Baidu academic
|Similar articles in Bing Scholar