Online measurement of tetraethyllead in aqueous samples utilizing monolith-base d magnetism-enhance d in-tub e solid phase microextraction coupled with chromatographic analysis

A new procedure that utilizing a preconcentration system based on magnetism-enhanced in-tube solid phase microextraction (ME/IT-SPME) and detection by HPLC with diode array detector (DAD) after liq-uid desorption from the microextraction column has been developed for the online measurement of tetraethyllead (TEL) in various aqueous samples. In this connection, according to the chemical features of TEL, porous monolith mingled with Fe3O4 nanoparticles were designed and synthesized in a silica cap-illary, and used as the microextraction column of ME/IT-SPME. To favor the implement of variable mag-netic fields during extraction procedure, the as-prepared microextraction column was twined a magnetic coil. Results revealed that the exertion of magnetic field during the adsorption and eluting procedures assisted the extraction of TEL with an enhancement by 52% in extraction efficiency. Under the most ben-eficial conditions, the developed ME/IT-SPME was online hyphenated with HPLC/DAD to measure trace TEL in various aqueous samples. The limit of detection was 0.082 mu g/L and the RSDs for precision were in the range of 6.3-8.5%. The recoveries with low, medium and high fortified levels varied from 80.6% to 95.0% with good repeatability. To the best of knowledge, this is the first study that using IT-SPME to extract TEL and then online quantification with HPLC/DAD.(c) 2023 Published by Elsevier B.V.

Automated summary

A new procedure using magnetism-enhanced in-tube solid phase microextraction (ME/IT-SPME) coupled with HPLC with diode array detector (DAD) has been developed for the online measurement of tetraethyllead (TEL) in aqueous samples. The ME/IT-SPME column, made of porous monolith mixed with Fe3O4 nanoparticles, was designed to incorporate a magnetic coil for the application of variable magnetic fields. The results showed a 52% improvement in extraction efficiency when a magnetic field was applied. The developed method demonstrated good precision, with a low limit of detection and high recovery rates.