Almeida C, Nogueira J M F
University of Lisbon, Faculty of Sciences, Chemistry and Biochemistry Department and Centre of Chemistry and Biochemistry, Campo Grande Ed. C8, 1749-016 Lisbon, Portugal.
University of Lisbon, Faculty of Sciences, Chemistry and Biochemistry Department and Centre of Chemistry and Biochemistry, Campo Grande Ed. C8, 1749-016 Lisbon, Portugal.
J Chromatogr A. 2014 Jun 27;1348:17-26. doi: 10.1016/j.chroma.2014.04.057. Epub 2014 Apr 24.
In the present work, the development of an analytical methodology which combines bar adsorptive microextraction with microliquid desorption followed by high performance liquid chromatography-diode array detection (BAμE-μLD/HPLC-DAD) is proposed for the determination of trace levels of four parabens (methyl, ethyl, propyl and buthyl paraben) in real matrices. By comparing six polymer (P1, P2, P3, P4, P5 and P6) and five activated carbon (AC1, AC2, AC3, AC4 and AC5) coatings through BAμE, AC2 exhibited much higher selectivity and efficiency from all the sorbent phases tested, even when compared with the commercial stir bar sorptive extraction with polydimethylsiloxane. Assays performed through BAμE(AC2, 1.7mg) on 25mL of ultrapure water samples spiked at the 8.0μg/L level, yielded recoveries ranging from 85.6±6.3% to 100.6±11.8%, under optimized experimental conditions. The analytical performance showed also convenient limits of detection (0.1μg/L) and quantification (0.3μg/L), as well as good linear dynamic ranges (0.5-28.0μg/L) with remarkable determination coefficients (r(2)>0.9982). Excellent repeatability was also achieved through intraday (RSD<10.2%) and interday (RSD<10.0%) assays. By downsizing the analytical device to half-length (BAμE(AC2, 0.9mg)), similar analytical data was also achieved for the four parabens, under optimized experimental conditions, showing that this analytical technology can be design to operate with lower volumes of sample and desorption solvent, thus increasing the sensitivity and effectiveness. The application of the proposed analytical approach using the standard addition methodology on tap, underground, estuarine, swimming pool and waste water samples, as well as on commercial cosmetic products and urine samples, revealed good sensitivity, absence of matrix effects and the occurrence of levels of some parabens. Moreover, the present methodology is easy to implement, reliable, sensitive, requiring low sample and minimized desorption solvent volume, having the possibility to tune the most selective sorbent coating, according to the target compounds involved.
在本研究中，提出了一种分析方法，该方法将棒状吸附微萃取与微液解吸相结合，然后进行高效液相色谱 - 二极管阵列检测（BAμE - μLD/HPLC - DAD），用于测定实际基质中痕量水平的四种对羟基苯甲酸酯（对羟基苯甲酸甲酯、乙酯、丙酯和丁酯）。通过棒状吸附微萃取（BAμE）比较六种聚合物（P1、P2、P3、P4、P5和P6）和五种活性炭（AC1、AC2、AC3、AC4和AC5）涂层，在所有测试的吸附剂相中，AC2表现出更高的选择性和效率，即使与商业化的聚二甲基硅氧烷搅拌棒吸附萃取相比也是如此。在优化的实验条件下，对25mL加标浓度为8.0μg/L的超纯水样品进行棒状吸附微萃取（AC2，1.7mg）分析，回收率在85.6±6.3%至100.6±11.8%之间。分析性能还显示出方便的检测限（0.1μg/L）和定量限（0.3μg/L），以及良好的线性动态范围（0.5 - 28.0μg/L），测定系数显著（r²>0.9982）。通过日内（RSD<10.2%）和日间（RSD<10.0%）分析也实现了出色的重复性。在优化的实验条件下，将分析装置尺寸缩小至一半长度（BAμE(AC2, 0.9mg)）时，对四种对羟基苯甲酸酯也获得了类似的分析数据，表明该分析技术可以设计为使用更少体积的样品和解吸溶剂进行操作，从而提高灵敏度和有效性。使用标准加入法将所提出的分析方法应用于自来水、地下水、河口、游泳池和废水样品，以及商业化妆品和尿液样品，结果显示出良好的灵敏度、无基质效应以及某些对羟基苯甲酸酯的存在水平。此外，本方法易于实施、可靠、灵敏，所需样品量少且解吸溶剂体积最小化，并且有可能根据所涉及的目标化合物调整最具选择性的吸附剂涂层。
