Lysine surface modified Fe3O4@SiO2@TiO2 microspheres-based preconcentration and photocatalysis for in situ selective determination of nanomolar dissolved organic and inorganic phosphorus in seawater
Lysine surface modified Fe3O4@SiO2@TiO2 microspheres-based preconcentration and photocatalysis for in situ selective determination of nanomolar dissolved organic and inorganic phosphorus in seawater
复制标题
基于赖氨酸表面修饰的Fe3O4@SiO2@TiO2微球的预富集和光催化原位选择性测定海水中纳摩尔溶解有机磷和无机磷
DOI：
10.1016/j.snb.2015.10.016
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发表时间：
2016-03-01
影响因子：
8.4
通讯作者：
Cai, Jiabai
中科院分区：
文献类型：
--
作者：
Li, Shunxing;Liang, Wenjie;Cai, Jiabai
提出了一种选择性测定海水中纳摩尔级溶解有机磷（DOP）和无机磷（DIP）的新的、灵敏的、快速的分光光度法。采用赖氨酸对Fe3O4@SiO2@TiO2（FST）微球进行表面修饰，并将其用作固相吸附剂、光催化剂和传感器。在用赖氨酸进行表面改性后，FST的Zeta电位-pH曲线可以反转，FST-Lys对海水中98.1%的DIP阴离子具有电吸附作用（1.2 mg/mL）在天然海水的pH值下（8.1-8.3）。吸附的DIP可用pH 4.0的盐酸溶液电排斥洗脱。因此，可以抑制DOP的酸水解，避免其对DIP测定的影响。磷钼蓝法可选择性地测定DIP。在UV照射后，DOP被FST-Lys光降解成DIP，溶解的磷的总浓度（即，DIP和DOP），然后可以计算DOP的浓度。FST-Lys可以很容易地通过施加外磁场回收，同时保持吸附和催化活性，即使在运行10次后也没有显着降低。该方法具有灵敏度高（检出限为1.42 nmol/L）、线性范围宽（3.0 ~ 1200 nmol/L）、选择性好等优点，已成功应用于南海和台湾海峡DIP和DOP的现场测定。(C)2015 Elsevier B. V.版权所有。
A new, sensitive, and rapid spectrophotometric method for selective determination of nanomolar levels of dissolved organic phosphorus (DOP) and inorganic phosphorus (DIP) in seawater was proposed. The microsphere of Fe3O4@SiO2@TiO2 (FST) was surface modified with lysine (FST-Lys) and used as solid phase adsorbent, photocatalyst, and sensor. After surface modification with lysine, the zeta potential vs pH curve for FST could be reversed and then 98.1% of DIP anions in the seawater could be specifically adsorbed by electric attraction onto FST-Lys (1.2 mg/mL) at the pH value of natural seawater (8.1-8.3) after only stirring for 30 min. The adsorbed DIP could be eluted with hydrochloric acid solution (pH 4.0) for electric repulsion. Therefore, acid hydrolysis of DOP could be inhibited and its influence on the determination of DIP could be avoided. DIP could be determined spectrophotometrically and selectively by phosphomolybdenum blue method. After UV irradiation, DOP was photodegraded by FST-Lys into DIP, the total concentration of dissolved phosphorus (i.e., DIP and DOP) could be determined, and then the concentration of DOP could be calculated. FST-Lys could be easily recycled by applying an external magnetic field while maintaining the adsorption and catalytic activity without significant decrease even after running 10 times. The proposed method with high sensitivity (detection limit of 1.42 nmol/L), wide linear range (3.0-1200 nmol/L), and selective determination was successfully applied for in situ measure of DIP and DOP in South China Sea and the Taiwan Channel. (C) 2015 Elsevier B.V. All rights reserved.