Gel electro-membrane extraction of propranolol and atenolol from blood serum samples: Effect of graphene-based nanomaterials on extraction efficiency of gel membrane.

In this work, gel electro-membrane extraction (G-EME) method is suggested for extraction and determination of propranolol and atenolol in complex biological samples. An in-house membrane based on agarose was used as green and biodegradable gel membrane. Essential chemical parameters that influence on extraction efficiency were tested, optimized and evaluated via a central composite design (CCD) and response surface methodology (RSM). Optimal conditions for extraction of drugs from the 7.0 mL sample were as follows: 3% (w/v) agarose with 0.1% (v/v) acetic acid functioning as membrane, voltage: 50 V; pH of the donor phase (DP): 8.1; pH of the AP: 3.3; extraction time: 35.9 min. Under these conditions, the acceptable normalized extraction recoveries were obtained such as 71.9 ± 5.4% that were in good agreement with the predicted values (i.e., 73.1 ± 0.9%). Limits of detection (LODs) for propranolol and atenolol were 5.0 ng mL and 7.5 ng mL, respectively. Moreover, for the first time, the effect of presence of four graphene-based nanomaterials such as graphene (G), graphene oxide (GO), three-dimensional nitrogen doped graphene oxide (3D-ND-GO) and high nitrogen doped graphene oxide (HND-GO) in agarose gel membrane on extraction efficiency, was investigated. The results showed that in presence of these nanomaterials, the normalized recovery depressed significantly due to increasing of electric current and electroendosmosis (EEO) phenomenon. Eventually, the proposed method was applied to quantify basic drugs in real plasma samples with relative recoveries in the range of 85.7-97.5%, indicating good reliability of the assay.