Sustainable magnetic solid-phase microextraction of alkylphenols in environmental waters using a novel polymeric magnetic hawthorn nanocomposite

• New magnetic nanocomposite developed based on recycling materials. • Fast magnetic solid phase extraction applied to alkylphenols determination. • Limit of detection values under the legislative requirements. • Application to real environmental samples. A novel polymeric magnetic nanocomposite obtained from hawthorn seeds MHSHC@PLA@C 18 was prepared by hydrothermal synthesis and applied to the extraction of alkylphenols (APs) such as: 4-octylphenol, 4- tert -octylphenol, and 4-nonylphenol from environmental water samples. The nanocomposite sorbent was characterized by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, and vibrating sample magnetometry, being a promising candidate for application as a sorbent in analytical applications. The developed material was employed to the magnetic solid phase extraction of APs from environmental water samples and its determination by gas chromatography-mass spectrometry (GC–MS) after analytes derivatization. Experimental variables influencing the MSPE procedure were thoroughly investigated, including sample volume, elution volume, ionic strength, sorbent amount, sample pH, and extraction time. The proposed method was validated in terms of accuracy (ranging the mean recoveries from 91 % to 116 %), and precision values expressed as % relative standard deviation under 20 %. The obtained limits of detection and quantification were in the range of 0.02–0.03 µg L -1 and 0.06–0.09 µg L −1 , respectively. The analytical method was successfully applied to 12 samples, including sewage and surface water samples, detecting APs in one sample at levels ranging from 0.115 to 0.126 µg L −1 . The results of this study suggested that MHSHC@PLA@C 18 has significant potential for the enhanced MSPE of APs from water samples. Additionally, the developed methodology was assessed from a Green Analytical Chemistry perspective using the Analytical GREEnness Metric Approach (AGREE) and the Blue applicability grade index (BAGI), obtaining a sustainability green score of 0.55 and a BAGI score of 62.5 for its applicability.