Membrane protected micro-solid-phase extraction of organochlorine pesticides in milk samples using zinc oxide incorporated carbon foam as sorbent

In this work, zinc oxide nanoparticles incorporated carbon foam was utilized as sorbent for extraction and preconcentration of fifteen organochlorine pesticides in milk samples. The sorbent was prepared by a fast and single step reaction between the sucrose and zinc nitrate that was accomplished by heating the mixture for 10 min. The resulting sorbent was characterized by scanning electron microscopy and X-ray diffraction. The sorbent was then employed in membrane protected micro-solid-phase extraction (μ-SPE) of OCPs in milk samples. This extraction technique is suitable for complex matrices such as milk because it provides effective protection of the sorbent inside the polypropylene membrane. The extracted samples were analyzed by gas chromatography mass spectrometry. The factors that affect the performance of μ-SPE were optimized. This method provided good linear range for all target compounds with coefficient of determinations up to 0.9998. Limits of detection ranged from 0.19 to 1.64 ng mL⁻¹. This method also provided satisfactory values for intra and inter-day precision with RSDs ranging between 2.3 to 10.2%.