Magnetic Porous Carbon Synthesized for MSPE-CE-DAD of Trace Bisphenols in the Environment

A study based out of the College of Chemistry and Chemical Engineering at China West Normal University in Nanchong, China is promoting the use of magnetic porous carbon (MPC) for solid-phase extraction (SPE) of bisphenol compounds (BP) in environmental samples, claiming the approach can be operated simply and repetitiously with high sensitivity (1).

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To be more precise, the MPC was synthesized as an adsorbent for a magnetic solid-phase extraction-capillary electrophoresis diode-array detection (MSPE-CE-DAD), successfully applied to the extraction and detection of BPs in water samples, as detailed in the report published in the Journal of Chromatography A.

MSPE-CE-DAD is a comprehensive analytical technique used for the extraction, separation, and detection of target compounds in complex samples. It involves the use of a magnetic adsorbent material, such as magnetic porous carbon (MPC), for solid-phase extraction (SPE) of the target analytes. The extracted analytes are then separated and analyzed using capillary electrophoresis (CE) coupled with a diode-array detector (DAD), which enables simultaneous detection of multiple wavelengths. This integrated approach offers several advantages, including high sensitivity, selectivity, and efficiency in the extraction and analysis of target compounds.

Bisphenol compounds (BPs) are crucial chemical raw materials for the synthesis of polymers, with bisphenol A (BPA) widely used in epoxy and phenolic resins as well as polycarbonate plastics. But long-term exposure to even low-level BPA poses a human health risk. BPA and other BPs have been observed to reduce fertility or reproductive development, be toxic to the renal nervous system, and cause malignant tumors including breast, ovarian, and testicular cancers. Therefore, the researchers characterize the need for an efficient and sensitive method of detecting trace levels as an urgent one.

Of the pretreatment methods most often associated with BP extraction, MSPE is the most used, and in this study was paired with capillary electrophoresis using an instrument equipped with an autosampler and diode-array detector. As for the choice of MPC, which loads magnetic nanoparticles onto porous carbon, the adsorbent takes advantage of porous carbon’s specific surface area, adsorption capacity, and chemical stability while facilitating both rapid separation and potential for reuse. In fact, the researchers said that the MPC could be easily recycled, and extraction efficiency stayed above 75% even with MSPE repeated five times.

The MPC was synthesized by one-step pyrolysis combined with a salvothermal method, and not only were the present BPs analyzed, but so was the performance of the MPC itself regarding adsorption. Standard stock solutions of four BPs – BPA, BPAF, TBBPA, and BPS – were prepared for this study.

Using this proposed method, the results showed that the detection limits for the quartet of BPs were between 0.71 and 1.65 ng/mL. Intra-day and inter-day precisions were between 2.27% and 4.03%, and 2.93% and 4.42%, respectively. Recoveries were measured from 87.68% to 108.0%.

Taking these numbers into account, the researchers found that MSPE-CE-DAD with MPC not only offered efficiency and potential for recycling, but might also be able to be used in other real-world applications of environmental sampling beside just BPs.

Reference

(1) Yang, X.; Zhang, M.; Yang, J.; et al. Sensitive determination of bisphenols in environmental samples by magnetic porous carbon solid-phase extraction combined with capillary electrophoresis. J. Chromatogr. A 2023, 1701, 464052. DOI: 10.1016/j.chroma.2023.464052