Environmental and Bio-Analytical Laboratories, Department of Chemistry Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran.
Environmental and Bio-Analytical Laboratories, Department of Chemistry Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran.
J Chromatogr A. 2019 Apr 26;1591:7-14. doi: 10.1016/j.chroma.2018.11.069. Epub 2018 Nov 26.
In this study, a method was described for the extraction of three antibiotic residues from cow milk samples using a graphene oxide-starch-based nanocomposite. The prepared nanocomposites were employed as an extractive phase for micro-solid phase extraction of antibiotics from cow milk samples. The extracted antibiotics, i.e. amoxicillin, ampicillin and cloxacillin, were subsequently analyzed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). Important variables associated with the extraction and desorption efficiency were optimized. High extraction efficiencies for the selected antibiotics were conveniently achieved using the starch-based nanocomposite as the extractive phase. The developed method was validated according to the European Commission Decision 2002/657/EC by spiking the selected antibiotics to the blank milk samples. The limits of quantitation (2.7-5.0 μg kg) were calculated for the selected penicillin group in milk samples and their quantities are lower than the maximum residue limits (MRLs). The obtained results indicate the remarkable efficiency of the graphene oxide-starch-based nanocomposite performance toward the selected antibiotics. The relative standard deviations of intra and inter-day analysis are less than 3.3 and 6.1%, respectively. Moreover, trueness of method was successfully accomplished via the recovery assays (88-102%) in the fortified blank milk samples with three different concentration levels (MRL, 1.5 MRL and 3 MRL μg kg). In overall, the proposed method was a promising alternative for analysis of selected three antibiotics in variety milk samples, due to the effective and easy-to-perform method and acceptable relative recovery in the range 83-105%.
本研究描述了一种使用氧化石墨烯-淀粉基纳米复合材料从牛奶样品中提取三种抗生素残留的方法。所制备的纳米复合材料被用作从牛奶样品中微固相萃取抗生素的萃取相。提取的抗生素，如阿莫西林、氨苄西林和氯唑西林，随后通过高效液相色谱-紫外检测（HPLC-UV）进行分析。与萃取和解吸效率相关的重要变量进行了优化。使用淀粉基纳米复合材料作为萃取相，方便地实现了所选抗生素的高萃取效率。该方法根据欧盟委员会第 2002/657/EC 号决定进行了验证，通过向空白牛奶样品中添加所选抗生素来进行验证。在所研究的牛奶样品中，青霉素类的定量限（2.7-5.0μgkg）被计算出来，其含量低于最大残留限量（MRL）。所得结果表明，氧化石墨烯-淀粉基纳米复合材料对所选抗生素具有显著的效率。日内和日间分析的相对标准偏差分别小于 3.3%和 6.1%。此外，通过在三个不同浓度水平（MRL、1.5 MRL 和 3 MRLμgkg）的加标空白牛奶样品中的回收试验成功完成了方法的准确性。总的来说，由于该方法有效且易于操作，相对回收率在 83-105%范围内，因此该方法是分析各种牛奶样品中所选三种抗生素的一种很有前途的替代方法。
