Development and comparison of four methods for the extraction of antibiotics from a vegetative matrix

Abstract

Studies have shown the potential for antibiotic uptake into food crops from irrigation water and soils containing pharmaceuticals. The objective of this study was to develop and compare methods quantifying uptake of antibiotics in food crops. Four methods were evaluated utilizing freeze and thaw cell lysing (FT), mechanical maceration (MAC), tissue sonication (SON), and microwave assisted solvent extraction (MASE). Four antibiotics (ciprofloxacin, lincomycin, oxytetracycline, and sulfamethoxazole) were tested representing four classes of antibiotics. The methods were evaluated based on method detection limits, analyte recoveries, and sample preparation time. The two most viable methods, FT and MAC, were used on replicate lettuce (Lactuca sativa) samples grown using irrigation water spiked with three of the antibiotic contaminants. Only lincomycin and sulfamethoxazole were detected in lettuce samples at concentrations as high as 1757 ng/g and 425 ng/g with detection of limits of 57 ng/g and 35 ng/g respectively. FT provided the highest level of extraction efficiency on environmental samples, required the least amount of sample preparation while providing adequate detection limits and reproducible analyte recovery. This article is protected by copyright. All rights reserved