Capsule phase microextraction of six bisphenols from human breast milk using a monolithic polyethylene glycol sorbent-based platform prior to high performance liquid chromatography-photo-diode array detection determination.

The determination of bisphenols in human breast milk is a matter of ongoing interest since it reveals the exposure levels in both lactating mothers, fetuses, and infants. Herein, capsule phase microextraction (CPME) is applied for the first time for the extraction of a mixture of bisphenols from human breast milk followed by their subsequent determination by high-performance liquid chromatography-photodiode array detection (HPLC-DAD). CPME is a recently introduced as an advanced micro preparative technique that meets the principles of Green Analytical Chemistry. Moreover, it integrates filtration, extraction and stirring mechanism into one single device, a composite attribute that allows selective extraction of analytes without any sample cleanup and facilitates faster extraction kinetics, resulting in enhancing the performance of the equilibrium-based extraction techniques that ensure better reproducibility and operational simplicity. Among four tested CPME devices, the sol-gel poly(ethylene glycol) capsules showed the best extraction efficiency. Critical factors of the extraction performance were investigated and optimized. The developed CPME-HPLC-PDA method was validated. Limits of detection and quantification were 7.58 ng/mL and 25 ng/mL, respectively. Relative recoveries were estimated between 89.7 and 110.5%, while the RSD values were <11% in all cases. CPME is poised to be a useful tool both for routine bioanalysis and research purposes.