Wang Jiali, Liu Ning, Zhao Guo, Wang Xiaochan, Liu Gang, Nguyen Thi Dieu Thuy, Zhang Litao
College of Engineering, Nanjing Agricultural University, Nanjing, 210031, People's Republic of China.
Key Lab of Modern Precision Agriculture System Integration Research, Ministry of Education of China, China Agricultural University, Beijing, 100083, People's Republic of China.
Environ Sci Pollut Res Int. 2023 Mar;30(14):41834-41847. doi: 10.1007/s11356-023-25242-y. Epub 2023 Jan 14.
A new strategy based on low-pressure ultraviolet (LPUV)-HO advanced oxidation photolysis for the quantitative determination of organic heavy metal ions (HMIs) in soil was proposed for the efficient, low-cost, accurate, and green detection of Pb(II) and Cd(II) in soil extracts by breaking the complexation of HMIs and organic matters, consequently restoring the ASV signals of target HMIs. The key parameters of the proposed LPUV-HO photolysis system for the restoration of stripping responses were optimized; the conversion of organic matter to inorganic matter during the photolysis was investigated by total organic carbon (TOC); the degradation kinetics of humic acid sodium (HAS) was measured by UV-vis spectroscopy (UV); the pathway of HAS converted to small molecule organics during degradation was observed by fluorescence spectroscopy (FS); additionally, Fourier transform infrared spectroscopy (FTIR) was used to study the complexation between HAS and HMIs. The results showed that the stripping signals of target HMIs in the simulated soil samples can be restored to nearly 100% with a good repeatability, and the restoration ratio of the stripping signal fluctuated within 10%. And the feasibility of the proposed method for the accurate detection of HMIs in the real soil samples was verified; the results showed that 93.7% of Cd(II) and 92.5% of Pb(II) in real soil extracts were detectable.
提出了一种基于低压紫外（LPUV）-羟基自由基（HO）高级氧化光解的新策略，用于定量测定土壤中的有机重金属离子（HMI），通过打破HMI与有机物的络合，从而恢复目标HMI的阳极溶出伏安（ASV）信号，实现对土壤提取物中Pb（II）和Cd（II）的高效、低成本、准确和绿色检测。对所提出的用于恢复溶出响应的LPUV-HO光解系统的关键参数进行了优化；通过总有机碳（TOC）研究了光解过程中有机物向无机物的转化；通过紫外可见光谱（UV）测定了腐殖酸钠（HAS）的降解动力学；通过荧光光谱（FS）观察了HAS在降解过程中转化为小分子有机物的途径；此外，利用傅里叶变换红外光谱（FTIR）研究了HAS与HMI之间的络合作用。结果表明，模拟土壤样品中目标HMI的溶出信号能够恢复到近100%，且具有良好的重复性，溶出信号的恢复率在10%以内波动。验证了所提方法用于准确检测实际土壤样品中HMI的可行性；结果表明，实际土壤提取物中93.7%的Cd（II）和92.5%的Pb（II）可被检测到。
