Synthesis of Graphene Oxide Based Sponges and Their Study as Sorbents for Sample Preparation of Cow Milk Prior to HPLC Determination of Sulfonamides

Abstract

In the present study, a novel, simple, and fast sample preparation technique is described for the determination of four sulfonamides (SAs), namely Sulfathiazole (STZ), sulfamethizole (SMT), sulfadiazine (SDZ), and sulfanilamide (SN) in cow milk prior to HPLC. This method takes advantage of a novel material that combines the extractive properties of graphene oxide (GO) and the known properties of common polyurethane sponge (PU) and that makes sample preparation easy, fast, cheap and efficient. The PU-GO sponge was prepared by an easy and fast procedure and was characterized with FTIR spectroscopy. After the preparation of the sorbent material, a specific extraction protocol was optimized and combined with HPLC-UV determination could be applied for the sensitive analysis of trace SAs in milk. The proposed method showed good linearity while the coefficients of determination (R2) were found to be high (0.991–0.998). Accuracy observed was within the range 90.2–112.1% and precision was less than 12.5%. Limit of quantification for all analytes in milk was 50 μg kg−1. Furthermore, the PU-GO sponge as sorbent material offered a very clean extract, since no matrix effect was observed.

The Current Role of Graphene-Based Nanomaterials in the Sample Preparation Arena

“…Therefore, high-performance sorbents packed into sample preparation hardware can be reusable many times, considering the compressibility factor, which can help unpack and recover these extractive phases. As examples, Maggira et al ( 2019 ) and Tang S. et al ( 2019 ) reported two self-recoverable graphene-aerogels which were successfully applied to the analysis of sulfonamides and phenolic compounds in complex matrices, respectively.…”

Sponges and Sponge-Like Materials in Sample Preparation: A Journey from Past to Present and into the Future

“…More importantly, the reusability of the prepared PUFs was examined, and it was found that they can last six months, after performing 15 sorption-desorption cycles each day, which is a great asset of the developed material. Finally, PUFs were functionalized with graphene oxide (GO) to combine the extractive properties of both [60]. The preparation process is very easy (stirring PUFs in GO solution and then drying at room temperature), but it takes more than 24 h to be completed.…”

“…Finally, PUFs were functionalized with graphene oxide (GO) to combine the extractive properties of both [ 60 ]. The preparation process is very easy (stirring PUFs in GO solution and then drying at room temperature), but it takes more than 24 h to be completed.…”

Sample Preparation Using Graphene-Oxide-Derived Nanomaterials for the Extraction of Metals

“…Graphene oxide (GO) is the oxidized form of graphene, which can be obtained from natural graphite powder through oxidation with an anhydrous mixture of sulfuric acid, sodium nitrate, and potassium permanganate [32]. Graphene and graphene oxide show a similar structure, which is composed of carbon atoms in sp 2 hybridization linked within a single-atom layer [33][34][35]. GO is of more polar and hydrophilic character than graphene, since it contains a large number of oxygen-containing groups including hydroxyl, carboxyl, and epoxy groups.…”

“…Graphene oxide sheets are negatively charged in aqueous solutions due to the ionization of carboxylic groups and since they contain oxygen atoms with a lone pair of electrons, they are ideal sorbents to bind metal ions both through ionic and coordinative interaction. The adsorbed metal ions can be subsequently eluted with the addition of acid with the H + competing for the binding site [10,35,36].…”