用于测定黑茶中铅的荧光增强化学传感器

摘要

An optical chemical sensing membrane based on reversible fluorescence enhancement of Erythromycin A immobilized in a plasticized poly (vinyl chloride) (PVC) membrane for Lead (Ⅱ) detection was developed. The membrane of the sensor consists of 50 mg of PVC, 100 mg of Di (2-ethylhexyl) phthalate and 2.94 mg of Erythromycin A. The maximum response of the sensing membrane to Lead (Ⅱ) was obtained in Tris/HCl buffer solution ( pH 8.0). Under optimal conditions, the proposed sensor responded linearly to Lead (Ⅱ) in the range of 4.00-6.00 mmol/L and had a detection limit of 0.10 μmol·L-1. The response time of the sensor was less than 50 s. In addition to the high reproducibility and reversibility of the fluorescence signal, the sensor also exhibited good selectivity. Except for Cr2O72- and MnO4-, it was not interfered by other common metal ions and anions. It was applied for the determination of Lead(Ⅱ) in a sample of FU Tea, which offered a satisfactory result.%铅(Ⅱ)对固定在增塑的聚氯乙烯(PVC)敏感膜中的红霉素A有可逆荧光增强作用,据此研制了测定铅(Ⅱ)的荧光化学传感器.该传感膜的组成为:50.0 mg PVC、100.0 mg邻苯二甲酸二异辛酯和2.94 mg红霉素A.该传感器在pH 8.0的Tris-HCl缓冲溶液中,测定铅(Ⅱ)的动力学范围为4.00~6.00 mmol·L-1,检出限为0.10μmol·L-1,响应时间小于50 s.该传感器具有良好的重现性、可逆性和选择性,除Cr2O72-和MnO4-外,常见阴离子和阳离子不干扰测定.该传感器应用于黑茶水样中铅(Ⅱ)含量的测定,结果与GB 5009.12—2010法一致.