Abstract:
Employing green analytical chemistry approaches to newly developed methods has extremely gained the interest of the analytical community and was intensely established in the past few years. The utilized solvents as well as the amount of produced waste have the chief impact on evaluating the greenness of the method. The present work is devoted to the development and the assessment of the greenness profile of three developed chromatographic methods for the quantitative estimation of sulfadiazine (SDZ) and trimethoprim (TMP) in bovine meat and chicken muscles using three evaluation tools; the “National Environmental Method Index” (NEMI), the “Analytical Eco-Scale” and the “Green Analytical Procedure Index” (GAPI). The developed methods have employed a variety of mobile and stationary phases and offered different quantification ranges. Conventional RP-HPLC with green aqueous-organic mobile phase was applied in Method I with the composition of water: ethanol (90: 10 v/v, pH = 5.5) utilizing a Gemini C18 column (150 × 4.6 mm, 5 µm) with linear ranges of 1–60 μg/mL for SDZ and 1–50 μg/mL for TMP. Micellar liquid chromatography (MLC) as an efficient green alternate was used in Method II with mobile phase composition of 0.1 M SDS, 12% isopropanol in 0.1 N citric acid buffered at pH 5.5 while utilizing an XTerra RP18 column (150 × 3.9 mm, 5 µm) and resulting in a linear range of 0.5–100 μg/mL for both drugs. UPLC-MS/MS as a high throughput analytical technique was utilized in Method III with a mobile phase composed of ammonium acetate: acetonitrile (80: 20 v/v, pH = 5.5) and an Acquity UPLC-BEH C18 column (50 × 2.1 mm, 1.7 μm), where the linear range was 0.1–2 μg/mL for both drugs. Thus, Methods II and III have permitted the estimation of the residues of SDZ and TMP at levels equivalent to their maximum residue limits. The three assessment tools have agreed that Methods II and III are the greenest developed methods, thus, recommending the utilization of MLC and UPLC-MS/MS as green, safe practice for estimating the drugs’ residues in food of animal origin.
