Introduction of high nitrogen doped graphene as a new cationic carrier in electromembrane extraction

Abstract

This paper proposes for the first time, the use of high nitrogen doped graphene (HND-G) as a new cationic carrier for the enhancement of electromembrane extraction (EME) performance. Sensitivity of EME was improved by the modification of supported liquid membrane composition through the addition of HND-G into 1-octanol for the extraction of naproxen and sodium diclofenac as model acidic drugs. The comparison between HND-G-modified EME and conventional EME showed that HND-G could increase the overall partition coefficient of acidic drugs in the membrane due to the fact that HND-G acts as an ion pair reagent and there is an electrostatic interaction between positively charged HND-G and acidic drugs with negative charge. During the extraction, model acidic drugs migrated from a 10 mL aqueous sample solution (pH 9.6) through a thin layer of 1-octanol containing 0.6% w/v of HND-G that was impregnated in the pores of a hollow fiber, into a 30 μL basic aqueous acceptor solution (pH 12.3) present in the lumen of the hollow fiber. Equilibrium extraction conditions were obtained after 16 min of operation with the whole assembly agitated at 1000 rpm. Under the optimized conditions, the enrichment factors were between 238 and 322 and also the LODs ranged from 0.1 to 0.7 ng/mL in different samples. Finally, the applicability of this method was evaluated by the extraction and determination of drugs of interest in real urine samples.

Electromembrane extraction–Recent trends and where to go

“…In addition to pure solvents, different SLM additives have been proposed recently to enhance mass transfer [12] , [36] , [38] , [40] , [41] . In one very interesting paper, the non-ionic macrocyclic compound bambus [6] uril was added to nitrobenzene and used as SLM for extraction of inorganic anions [12] .…”

“…Such positive effect of graphene oxide nano-sorbents was further supported by EME of chloramphenicol from dairy products [42] . In a fourth paper, nitrogen doped graphene was tested as SLM additive [40] . This material was dispersed into octanol, and served as cationic carrier for enhanced extraction of negatively charged naproxen and diclofenac from urine.…”