simultaneous microextraction and concentration of lead (ii), zinc (ii) and silver (i) in carbon nanotube sol−gel composite immobilized hollow fiber membranes

Hollow fiber-solid phase microextraction (hf-spme) technique containing multiwalled carbon nanotubes (mwcnts) reinforced sol-gel nanocomposite coupled with uv–vis spectrophotometry was applied for preconcentration and determination of lead, zinc and silver in water samples. in this technique, a high efficiency sorbent containing mixture of mwcnts and a microporous gel was injected into a piece of a polypropylene hollow fiber for in situ gelation. the method validation was included and satisfying results were obtained. it owes large surface area and porosity of the nano-adsorbent. under the optimal conditions, linear calibration curves were established for the concentration of pb^2+, zn^2+ and ag^+ in the range of 0.2–7.0, 0.3–7.0 and 2.0–50 μg/ml respectively. the limits of detection were 0.032, 0.057 and 0.325 μg/ml for pb^2+, zn^2+ and ag^+. the relative standard deviations (rsds) were found to be less than 8.0 %.