Department of Analytical Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
Department of Analytical Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
Food Chem. 2019 Mar 15;276:255-261. doi: 10.1016/j.foodchem.2018.10.035. Epub 2018 Oct 9.
Zwitterionic dispersive magnetic solid phase extraction (ZI-DMSPE) was developed through in situ binding of glycine on the magnetic graphene oxide, electrostatically. This highly selective sorbent was applied for the determination and preconcentration of trace levels of nitrite in soil, sausage, water samples (tap, mineral, and rain), and vegetables (potato, onion, spinach, radish, and lettuce) prior to its determination by UV-Vis spectrophotometry. The major advantage of the method is the analyte adsorption in both acidic and basic media. The sorbent was characterized by SEM, XRD, EDS, and FT-IR. Several parameters affecting ZI-DMSPE were optimized. Under the optimal conditions, LOD and RSD were obtained 17 ng L and 1.3% respectively. Preconcentration factor and sorption capacity of the proposed method were 666 and 238 mg g respectively. Accuracy was assessed by comparing results with those obtained by direct determination using ion chromatography and spiked real samples.
两性离子分散磁性固相萃取（ZI-DMSPE）通过原位静电结合在磁性氧化石墨烯上的甘氨酸发展而来。这种高选择性的吸附剂被用于测定和预浓缩土壤、香肠、水样（自来水、矿泉水和雨水）和蔬菜（土豆、洋葱、菠菜、萝卜和生菜）中的痕量亚硝酸盐，然后通过紫外分光光度法进行测定。该方法的主要优点是在酸性和碱性介质中都可以吸附分析物。采用 SEM、XRD、EDS 和 FT-IR 对吸附剂进行了表征。优化了影响 ZI-DMSPE 的几个参数。在最佳条件下，LOD 和 RSD 分别为 17ng/L 和 1.3%。该方法的预浓缩因子和吸附容量分别为 666 和 238mg/g。通过与直接使用离子色谱法测定和加标实际样品的结果进行比较，评估了准确性。
