São Carlos Institute of Chemistry, University of São Paulo, 13566-590, São Carlos, SP, Brazil.
São Carlos Institute of Chemistry, University of São Paulo, 13566-590, São Carlos, SP, Brazil.
J Chromatogr A. 2019 Jun 21;1595:66-72. doi: 10.1016/j.chroma.2019.02.036. Epub 2019 Feb 16.
A high-throughput and innovative setup has been developed to automate the online integration of single drop microextraction (SDME), liquid chromatography (LC) and high-resolution mass spectrometry (QqToF). SDME and LC were online hyphenated for the first time. SDME was carried out by a lab-made cartesian robot actuating a 100 μL syringe, equipped with a three-way solenoid microvalve that allowed the online transference of the enriched extract to the chromatographic system, through a six-port switching valve. The complete method, including the synchronized robot action, valves, and the analytical instruments, was controlled by an Arduino Mega board. The merits of the proposed setup were demonstrated by the triazines determination in coconut water samples. The most relevant extraction parameters, such as drop size, exposure time, stirring effect, salt addition and pH were systematically investigated. Under optimized conditions (60 μL drop volume and 10 min extraction time), the LC-UV enrichment factors (EF) and the extraction recoveries (ER) ranged between 15.2-18.4 and 11.4-13.8%, respectively. Using the SDME-LC-MS setup, the linear range, detection limit (S/N = 3) and precision (RSD, n = 6 at 0.25 μg L level of concentration) were 0.25-25 μg L, 0.10 μg L and 16.8% for simazine; 0.25-25 μg L, 0.05 μg L and 14.7% for atrazine; and 0.25-25 μg L, 0.05 μg L and 18.5% for propazine, respectively. Although none of the analytes were detected in the evaluated commercial samples, the results indicate that the proposed online SDME-LC setup is a competitive analytical strategy for the determination of target organic compounds in complex matrices.
已开发出一种高通量和创新的设置，以实现单滴微萃取（SDME）、液相色谱（LC）和高分辨率质谱（QqToF）的在线自动集成。首次在线连接 SDME 和 LC。通过由实验室制造的笛卡尔机器人进行 SDME，该机器人驱动 100 μL 注射器，配备三通电磁阀微阀，可通过六通切换阀将富集的提取物在线转移到色谱系统。完整的方法，包括同步机器人动作、阀门和分析仪器，由 Arduino Mega 板控制。通过椰子水样品中三嗪的测定证明了所提出的设置的优点。系统研究了最相关的提取参数，如液滴大小、暴露时间、搅拌效果、加盐和 pH 值。在优化条件下（60 μL 液滴体积和 10 分钟提取时间），LC-UV 富集因子（EF）和提取回收率（ER）分别在 15.2-18.4 和 11.4-13.8%之间。使用 SDME-LC-MS 装置，线性范围、检测限（S/N=3）和精密度（在 0.25μg/L 浓度水平下 n=6 的 RSD）分别为 0.25-25μg/L、0.10μg/L 和 16.8%的西玛津；0.25-25μg/L、0.05μg/L 和 14.7%的莠去津；0.25-25μg/L、0.05μg/L 和 18.5%的扑灭津。尽管在所评估的商业样品中均未检测到分析物，但结果表明，所提出的在线 SDME-LC 装置是一种用于测定复杂基质中目标有机化合物的有竞争力的分析策略。
