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Advancements in capacitance‐to‐digital converter‐based C 4 D technology for detection in capillary electrophoresis using amplified excitation voltages and comparison to classical and open‐source C 4 Ds
Author(s) -
Graf Hannes Georg,
Rudisch Benjamin Maximilian,
Manegold Johanna,
Huhn Carolin
Publication year - 2021
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.202000394
Subject(s) - capillary electrophoresis , excitation , capacitance , analytical chemistry (journal) , voltage , electrophoresis , chemistry , physics , optoelectronics , materials science , atomic physics , chromatography , electrode , quantum mechanics
This work introduces new hardware configurations for a capacitively coupled contactless conductivity detector (C 4 D) based on capacitance‐to‐digital conversion (CDC) technology for CE. The aim was to improve sensitivity, handling, price, and portability of CDC‐based C 4 D detectors (CDCD) to reach LODs similar to classic C 4 Ds with more sophisticated electric circuits. To achieve this, a systematic study on the CDCDs was carried out including a direct comparison to already established C 4 D setups. Instrumental setups differing in electrode lengths, measurement modes, and amplification of excitation voltages were investigated to achieve LODs for alkali metal ions of 4 to 12 μM, similar to LODs obtained by classic C 4 D setups. Lowest LODs were achieved for a setup with two 10 mm electrodes at a distance of 0.2 mm and an excitation voltage of 24 V. The detection head was exceptionally lightweight with only 2.6 g and covered only 20 mm of the capillary on total. This allowed the use of multiple detectors along the separation path to enable spatial tracking of analytes during separation. The entirely battery‐powered detector assembly weighs less than 200 g, and the data are transmitted wirelessly for possible portable applications. The freely accessible hardware and software were optimized for fully automated measurements with real time data plotting and allowed handling multidetector setups. The new developments were applied to quantify the potassium salt of glyphosate in its herbicide formulation.