3D printed cartridge for high-speed capillary electrophoresis with sheath liquid thermostatting and contactless conductivity detection

Anal Chim Acta. 2023 Jul 11;1264:341235. doi: 10.1016/j.aca.2023.341235. Epub 2023 Apr 29.ABSTRACTThe high-speed capillary electrophoresis (HSCE) method is a technique that utilizes a high electric field strength applied through a short capillary to reduce the time required for sample separation. However, the increased electric field strength may result in pronounced Joule heating effects. To address this, we describe a 3D-printed cartridge with integrated contactless conductivity detection (C4D) head and a sheath liquid channel. The C4D electrodes and Faraday shield layers are fabricated by casting Wood's metal in chambers inside the cartridge. Effective thermostatting of the short capillary is achieved by flowing Fluorinert liquid, which provides better heat dissipation compared to airflow. A HSCE device is created by using the cartridge and a modified slotted-vial array sample-introduction approach. Analytes are introduced through electrokinetic injection. With the help of sheath liquid thermostatting, background electrolyte concentration can be increased to several hundred mM, resulting in improved sample stacking and peak resolutions. Additionally, the baseline signal is flattened. Typical cations such as NH4+, K+, Na+, Mg2+, Li+, and Ca2+ can be separated within 22 s with an applied field strength of 1200 V/cm. The limit of detection ranges from 2.5 to 4.6 μM with a relative standard deviation of migration times of 1.1-1.2% (n = 17). The method has been applied to dete...

Source: Analytica Chimica Acta - May 25, 2023 Category: Chemistry Authors: Xing Liu Wenshan Liang Hui Zeng Yiyu Jiang Yan Li Min Zhang Source Type: research