C18-modified halloysite as a novel sorbent in matrix solid-phase dispersion for the extraction of bisphenol A and diethylstilbestrol from human placenta

In the current study, the C18-modified halloysite was fabricated via silylation reaction and subsequently used as sorbent in matrix solid-phase dispersion (MSPD) for the extraction of bisphenol A and diethylstilbestrol from human placenta, followed by high-performance liquid chromatography-tandem mass spectrometry analysis. The as-prepared sorbent was characterized by scanning electron microscopy, energy-dispersive spectrometry, Fourier transform infrared spectroscopy, X-ray diffraction, and thermo-gravimetric analysis. Varied parameters such as methanol concentration in wash solvent, pH and salt concentration in elution solvent, elution volume, and mass ratio of sample to sorbent were optimized. The adsorption capacities of bisphenol A and diethylstilbestrol on the developed C18-modified halloysite were 6.3 and 14.2 mg g^-1, respectively, higher than those on the commercial C18 silica gel. Under the optimal condition, the average recoveries of bisphenol A and diethylstilbestrol by MSPD varied from 91.0 to 106.0%, and the relative standard deviations were less than 10.6% for human placenta samples. The limits of detection in the human placenta were 0.2 μg kg^-1 for bisphenol A and diethylstilbestrol. The simple C18-modified halloysite-based MSPD method holds great potential for the determination of trace bisphenol A and diethylstilbestrol in the human placenta and other tissues of pregnant women with high sensitivity, accuracy, and reliability.

(Hong-hua)

A simple and low-cost method based on matrix solid-phase dispersion (MSPD) extraction, HPLC separation, diode array detection and UPLC-Q-TOF-MS have been developed for the determination of Hydroxysafflor yellow A (HSYA), Kaempferol and other main compounds in Carthamus tinctorius. The experimental parameters that may affect the MSPD method, including dispersing sorbent, ratio of dispersing sorbent to sample, elution solvent, and volume of the elution solvent were examined and optimized. The optimized conditions were determined to be that silica gel was used as dispersing sorbent, the ratio of silica gel to sample mass was selected to be 3:1, and 10 mL of methanol: water (1:3, v:v) was used as elution solvent. The highest extraction yields of the two compounds were obtained under the optimized conditions. The method showed good linearity (r(2)≥0.999 2) and precision (RSD≤3.4%) for HSYA and Kaempferol, with the limits of detection of 35.2 and 14.5 ng mL(-1), respectively. The recoveries were in the range of 92.62-101.7% with RSD values ranging from 1.5 to 3.5%. At the meanwhile, there were 21 compounds in the extraction by MSPD method were identified by TOF-MS method to improve the quality control for safflower. Comparing to ultrasonic and soxhlet methods, the proposed MSPD procedure was more convenient and less time-consuming with reduced requirements on sample and solvent amounts. The proposed procedure was applied to analyze four real samples that were collected from different localities.