Modification of garlic peel by nitric acid and its application as a novel adsorbent for solid-phase extraction of quinolone antibiotics

Abstract

Garlic peel, an agriculture by-product, was modified by a simple method using HNO3, and the adsorption behaviors of garlic peel (GP) and HNO3 modified garlic peel (HNO3-GP) for quinolone antibiotics were evaluated. Furthermore, HNO3-GP was used as a novel solid-phase extraction (SPE) sorbent for the detection of quinolone antibiotics for the first time. Comparisons of characterizations between GP and HNO3-GP revealed that the increase of surface acidic functional group of HNO3-GP led to a significant improvement of adsorption capacity (about 10 times of GP). In addition, the adsorption behaviors of GP and HNO3-GP for quinolone antibiotics including adsorption kinetic, isotherm and thermodynamic studies were discussed, and the results proved that HNO3-GP have higher affinity of quinolones. Moreover, key parameters influencing the relative recoveries of HNO3-GP based SPE, such as the content of eluent, the volume of eluent, the pH of water sample and the sorbent amount were investigated. Finally, an environmentally friendly, effective and economic HNO3-GP based SPE-HPLC method for the determination of four quinolone antibiotics was established, and successfully applied in the analysis of real sample. Under the optimized conditions, good liner relationships (>0.9996), limits of detections (LODs) from 0.65 to 0.85μgL−1, and relative recoveries from 86.3 to 95.1% with satisfactory analytical features (relative standard deviation, RSD, <4.1%, n=3) were obtained. This work provides a new utilization method for agriculture by-product and makes them practical in pretreatment method of emerging organic pollutants in the environment.