Automated dispersive liquid-liquid microextraction based on the solidification of the organic phase

• Published in: Talanta (Oxford) 2018-11, Vol.189, p.241-248
• Main Authors: Medina, Deyber Arley Vargas, Santos-Neto, Álvaro José, Cerdà, Víctor, Maya, Fernando
• Format: Article
• Language: English
• Subjects: 3D printing; Dispersive liquid-liquid microextraction; Flow analysis; In-syringe extraction; Open-source robotics; Solidification of the organic phase
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2018.06.081

In this work, the dispersive liquid-liquid microextraction technique based on the solidification of the organic phase (DLLME-SFO) has been automated for the first time. DLLME-SFO is automated by hyphenating a sequential injection analysis (SIA) system with a custom-made robotic phase separator. Automated in-syringe DLLME is followed by phase separation in a 3D printed device integrating a Peltier cell set, mounted on a multi-axis robotic arm. The combined action of the flow system and the robotic arm is controlled by a single software package, enabling the solidification/melting and collection of the organic phase for further analyte quantification. As proof-of-concept, automated DLLME-SFO was applied to the extraction of parabens followed by separation using liquid chromatography, obtaining LODs between 0.3 and 1.3 µg L−1 (4 mL of sample extracted in 1 mL of 1-dodecanol: MeOH, 15:85, v-v). The method showed a high reproducibility, obtaining intraday RSDs between 4.6% and 5.8% (n = 6), and interday RSDs between 5.6% and 8.6% (n = 6). The developed method was evaluated for the determination of parabens in water, urine, saliva, and personal care products. [Display omitted] •Automation of dispersive liquid-liquid microextraction based on the solidification of the organic phase.•Hyphenation of flow-based techniques with robotics.•Design of 3D printed phase separators for liquid-liquid extraction.•Automated sample preparation of parabens from different sample matrices.