Simultaneous Determination of a Polychlorinated Dibenzo-p-Dioxin and Dibenzo-p-Furan in Environmental Water by Dispersive Liquid-Liquid Microextraction (DLLME) and a Modified QuEChERS Procedure with High-Performance Liquid Chromatography – Diode Array Detection (HPLC-DAD)

Abstract

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are persistent organic pollutants frequently detected in air, soil, and water. Thus, monitoring these compounds in environmental compartments is fundamental to identifying potential risks to human health. However, studies of analytical methods for PCDD/Fs extraction in water are still limited. Therefore, this study aimed to optimize and validate a dispersive liquid-liquid microextraction (DLLME) and QuEChERS method combined with high-performance liquid chromatography – diode array detection (HPLC-DAD) to determine 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF) in water samples. The proposed methods were optimized to achieve higher recovery rates for PCDD/Fs extraction. DLLME and QuEChERS combined with HPLC-DAD were validated according to SANTE guidelines to ensure reliability and applicability. The recoveries of both methods ranged from 93.5 to 105.5%, and relative standard deviations were less than 12%. The analytical validation certified that the proposed methods were selective, precise, accurate, and linear, with limits of quantification ranging from 2.4 to 5.3 μg L⁻¹. These results suggested the feasibility of DLLME and modified QuEChERS combined with HPLC-DAD as simple, inexpensive, and environmental-friendly approaches for monitoring PCDD/F in aqueous samples.

Keywords:

• 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD)
• 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF)
• dispersive liquid-liquid microextraction (DLLME)
• modified QuEChERS
• high-performance liquid chromatography – diode array detection (HPLC-DAD)

Acknowledgments

The authors thank the Universidade Federal de Minas Gerais (UFMG) and the Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) for the infrastructure provided. The authors also thank the Laboratório de Quimica Instrumental of the Universidade Federal de Minas Gerais (LQI-UFMG) by the available infrastructure.

Additional information

Funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES) - Finance Code 001, the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (420637/2016-8 and 308480/2019-8), and the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) (APQ-02736-21).