Arismendi Daniel, Vera Iván, Ahumada Inés, Richter Pablo
Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, P.O. Box 233, Santiago, Chile.
Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, P.O. Box 233, Santiago, Chile.
Anal Chim Acta. 2023 Apr 29;1252:341053. doi: 10.1016/j.aca.2023.341053. Epub 2023 Mar 7.
The features and nature of the sorptive phase may be the stage that determines the scope of microextraction techniques. In search of new alternatives, materials of natural origin have recently been explored to establish greener analytical strategies. Based on that search, this research proposes the use of chitosan as a sorptive phase, which was assessed in the rotating disk sorptive extraction of emerging contaminants from aqueous systems. Chitosan is a biopolymer of animal origin that is usually found in the shells of crustaceans. The main characteristic of this material is the presence of a high number of nitrogenous groups, which gives it high reactivity, but its main disadvantage is associated with its high swelling capacity. In this research, chitosan was crosslinked with a low concentration of glutaraldehyde to form thin films that were easily immobilized on the surface of the rotating disk. The main advantage of this modification is the considerable decrease in the swelling capacity, which prevents loss and rupture of the sorbent during high rotation of the disk. In addition, it not only improved the physical characteristics of chitosan but also increased its extraction capacity. With regard to its use as a sorptive phase, all the variables associated with the microextraction of the analytes were studied, and optimal variables were found to be: pH 4, 20% NaCl (salting out effect), 30-45 min as equilibrium time and elution of analytes with a mixture of methanol:ethyl acetate (1:1). Validation of the methodology for the determination of methyl triclosan and triclosan was carried out, and relative recoveries between 89 and 96% and relative standard deviations less than 14% were found. The detection limits were 0.11 and 0.20 μg L, respectively. Through its application in real samples (natural and residual waters), triclosan was quantified between 0.7 and 1.3 μg L. Finally, the "green" properties of the phase were evaluated, demonstrating that it is reusable for at least three cycles and biodegradable. Compared to its efficiency with a commercial phase (in this case, the styrene divinyl benzene phase), the proposed biosorbent provided a similar and even higher sorptive capacity (depending on the analyte).
吸附相的特性和性质可能是决定微萃取技术范围的阶段。为了寻找新的替代方法，最近人们探索了天然来源的材料，以建立更环保的分析策略。基于这一探索，本研究提出使用壳聚糖作为吸附相，并在旋转盘吸附萃取水性体系中新兴污染物的过程中对其进行了评估。壳聚糖是一种动物源生物聚合物，通常存在于甲壳类动物的外壳中。这种材料的主要特点是含有大量含氮基团，这赋予了它高反应活性，但其主要缺点与它的高膨胀能力有关。在本研究中，壳聚糖与低浓度的戊二醛交联形成薄膜，这些薄膜易于固定在旋转盘的表面。这种改性的主要优点是膨胀能力显著降低，这防止了吸附剂在盘高速旋转时的损失和破裂。此外，它不仅改善了壳聚糖的物理特性，还提高了其萃取能力。关于其作为吸附相的使用，研究了与分析物微萃取相关的所有变量，发现最佳变量为：pH值4、20%氯化钠（盐析效应）、30 - 45分钟作为平衡时间以及用甲醇:乙酸乙酯（1:1）混合物洗脱分析物。对测定甲基三氯生和三氯生的方法进行了验证，相对回收率在89%至96%之间，相对标准偏差小于14%。检测限分别为0.11和0.20 μg/L。通过在实际样品（天然水和残留水）中的应用，三氯生的定量结果在0.7至1.3 μg/L之间。最后，对该相的“绿色”特性进行了评估，结果表明它至少可重复使用三个循环且可生物降解。与商业相（在这种情况下为苯乙烯二乙烯基苯相）的效率相比，所提出的生物吸附剂具有相似甚至更高的吸附能力（取决于分析物）。
