New Method Enables Online Measurement of Tetraethyllead in Aqueous Samples

Researchers have developed a breakthrough method for the online measurement of tetraethyllead (TEL) in various aqueous samples, offering a significant advancement in the analysis of this toxic compound. The study, led by Xiaojing Li from Fuzhou University and Xiamen University in China, utilized a preconcentration system based on magnetism-enhanced in-tube solid phase microextraction (ME/IT-SPME) coupled with high performance liquid chromatography (HPLC) and a diode array detector (DAD). This work was published in the Journal of Chromatography A.

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ME/IT-SPME is a technique used for the extraction and preconcentration of analytes from various samples. It involves the use of a magnetic field to enhance the efficiency of solid phase microextraction (SPME). In this method, a magnetic material, such as Iron (II, III) oxide or magnetite (Fe₃O₄) nanoparticles, is incorporated into a porous monolith inside a capillary. The magnetic field assists in the adsorption and elution of the target analytes, improving the extraction efficiency. ME/IT-SPME offers advantages such as increased extraction efficiency, reduced extraction time, and improved sensitivity.

Tetraethyllead is a highly toxic organometallic compound that was commonly used as an antiknock additive in gasoline. Due to its adverse effects on human health and the environment, monitoring and analyzing TEL levels in water sources have become crucial for environmental protection and public safety.

The research team developed a novel approach by designing and synthesizing a porous monolith mingled with Fe₃O₄ nanoparticles, which was incorporated into a silica capillary. This monolith-based microextraction column served as the core component of the ME/IT-SPME system. To enhance the extraction efficiency, a magnetic coil was wrapped around the microextraction column, enabling the implementation of variable magnetic fields during the adsorption and elution procedures.

The results of the study demonstrated a significant enhancement of 52% in the extraction efficiency of TEL when a magnetic field was applied. Under optimized conditions, the developed ME/IT-SPME method was online coupled with HPLC-DAD to measure trace amounts of TEL in various aqueous samples.

The researchers achieved a remarkable limit of detection of 0.082 μg/L, indicating the method's high sensitivity in detecting TEL. Moreover, the precision of the method was demonstrated by relative standard deviations (RSDs) ranging from 6.3% to 8.5%, ensuring reliable and reproducible results. The recoveries of TEL at low, medium, and high fortified levels were also satisfactory, ranging from 80.6% to 95.0%.

Importantly, this study represents the first application of in-tube solid phase microextraction (IT-SPME) for the extraction of tetraethyllead, followed by online quantification using HPLC-DAD. The method offers numerous advantages, including its capability for online analysis, high sensitivity, and robust performance. By enabling the direct and efficient measurement of TEL in aqueous samples, this method holds great potential for environmental monitoring, industrial processes, and regulatory compliance.

The development of sensitive and accurate analytical techniques is crucial for the effective monitoring and control of harmful substances in our environment. The innovative ME/IT-SPME approach presented in this study represents a significant step forward in the field of analytical chemistry, offering a powerful tool for the detection and quantification of tetraethyllead in aqueous samples. The researchers envision that this method will contribute to enhanced environmental monitoring efforts and aid in ensuring the safety and well-being of communities worldwide.

Reference

(1) Song, X.; Meng, X.; Chen, M.; Wang, L.; Li, X.; Huang, X. Online measurement of tetraethyllead in aqueous samples utilizing monolith-based magnetism-enhanced in-tube solid phase microextraction coupled with chromatographic analysis. J. Chromatogr. A 2023, 1700, 464040. DOI: 10.1016/j.chroma.2023.464040