Graphene particles supported on silica as sorbent for residue analysis of tetracyclines in milk employing microextraction by packed sorbent

Abstract

This paper describes the use of graphene-based sorbents for determination of four tetracyclines in milk. The synthesized materials were combined with microextraction by packed sorbent (MEPS) to act as the sample preparation step. The extraction performance of these sorbents was compared to commercial phases, and graphene supported on silica provided the best results. The analytical method optimization was carried out by employing experimental design. Firstly, an evaluation of the experimental variables (elution solvent, use of EDTA, ionic force, and pH of the washing solution) was made by a 2 factorial experimental design. The variables sampling, washing and elution cycles of MEPS were further optimized under a full 2 experimental design. The validation parameters were determined under optimized conditions resulting in a linearity ranging from 15 to 110 μg/L with R values above 0.98, and LOQs ranging from 0.05 to 0.9 μg/L. The accuracy ranged from 87.9 to 118.4% and intra/inter-day precision reported by the RSDs were lower than 19%. The proposed and validated method was successfully applied to the analysis of 11 milk samples from different animals, revealing traces of tetracyclines in only two of them. This study focused on the evaluation of graphene-based sorbents combined with MEPS for tetracycline analysis provided equivalent or even better results than other proposed methods, suggesting being a sensitive, fast and reliable alternative method for the determination of tetracyclines in milk samples.

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

“…The authors achieved low LODs and LOQs in a complex matrix (coffee samples) by using these particles in a packed in-tube SPME device (Mejía-Carmona and Lanças, 2020 ). Other interesting graphene-based applications carried out by the Lança's research group also includes tetracyclines' analysis in milk samples (Vasconcelos Soares Maciel et al, 2018 ) and the determination of triazines in environmental water samples (De Toffoli et al, 2018 ).…”

Multidimensional Liquid Chromatography Employing a Graphene Oxide Capillary Column as the First Dimension: Determination of Antidepressant and Antiepileptic Drugs in Urine

“…This behavior can be explained due to the lower pH (≈3.2) obtained when formic acid (FA) is used, which can favor the interactions between the analytes and the sorbent phase. In this pH range, most molecules are charged and consequently have more affinity for the polar oxygen groups present on the graphene oxide surface [17,18]. Apart from that, using methanol and acetonitrile in the loading phase is expected to produce a higher elution strength, which makes the sorption of the analytes in the extraction column difficult; they pass directly through it, going to waste.…”

“…Furthermore, MS grade formic acid (FA) acquired from Sigma-Aldrich (St Louis, MO, USA) was used to acidify the chromatographic mobile phases. The GO-Sil extractive phase was synthesized and had already been used in previous works published by our research group [16,18].…”

Current status and future trends on automated multidimensional separation techniques employing sorbent‐based extraction columns

“…According to our point of view, a more detailed investigation about the extraction parameters should be done aiming to optimize the process in order to improve the peak resolution for some of the investigated compounds. The main feature of this novel and interesting approach is to produce capillary tubes packed with graphene‐based material that does not require additional chemical reagents, in opposition to recently reported similar studies that show the GO coating process produced in organic media with the addition of organic chemical reagents . The automated analytical method was validated and applied to the analysis of industrial sewage samples (wastewater and cooking plants) with residues of PAHs being found in both.…”