Hexagonal Boron Nitride Nanosheets Based Magnetic Solid Phase Extraction for the Extraction of Phenoxy Carboxylic Acid Herbicides from Water Samples Followed by HPLC-MS/MS Determination

Abstract

A kind of hexagonal boron nitride nanosheets-based magnetic composite (Fe 3 O 4 @h-BNNSs) was designed and applied for the determination of five phenoxy carboxylic acid (PCA) herbicides from water samples combined with high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The Fe 3 O 4 @h-BNNSs composite was synthesized via a facile two-step preparation method, and then characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). Several main variables influencing the extraction efficiencies of PCA herbicides were investigated and optimized in detail, such as amount of adsorbents, extraction time, pH of the sample solution, ionic strength, type of desorption solvent, and so on. In this work, π-π interaction, hydrogen bond and halogen bond provided the main driving force for the adsorption of PCA herbicides onto the Fe 3 O 4 @h-BNNSs composite. Under the most favorable conditions, the proposed method displayed good linear ranges (20.0-10000.0 ng L −1 ), low limits of detection (7.6-30.0 ng L -1 ), satisfactory precisions (1.1-6.8%) and recoveries (76.6-107.2%). Overall, the present work can be a versatile and worthy utility for the determination of PCA herbicides from different water samples.

Keywords: Hexagonal boron nitride nanosheets, Magnetic solid-phase extraction, Phenoxy carboxylic acid herbicides, HPLC-MS/MS, Water samples