Capacitively coupled contactless conductivity detection (C4D) is an interesting tool to detect molecules with no strong UV-absorbing chromophore. It is mainly combined with capillary electrophoresis (CE) and was proven to be a versatile mode of detection. After a short technical explanation, the paper will focus on the possible use of CE-C4D in quality control of aminoglycoside antibiotics which in general, do not show UV absorption and thus pose a serious challenge for direct detection. It will be shown that CE-C4D can be applied for the separation of kanamycin, tobramycin and amikacin from their respective impurities. Baseline separation was obtained using similar background electrolytes composed of 2-(N-morpholino) ethanesulfonic acid and histidine. As the methods should be useful for the determination of small amounts of impurities, special attention was paid to the sensitivity of the CE-C4D methods.
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