Determination of salidroside and tyrosol in Rhodiola by capillary electrophoresis with graphene/poly(urea‐formaldehyde) composite modified electrode

This report describes the fabrication and application of a novel graphene/poly(urea‐formaldehyde) composite modified electrode as a sensitive amperometric detector of CE. The composite electrode was fabricated on the basis of the in situ polycondensation of a mixture of graphenes and urea–formaldehyde prepolymers on the surface of a platinum disc electrode. It was coupled with CE for the separation and detection of salidroside and tyrosol in Rhodiola, a traditional Chinese medicine, to demonstrate its feasibility and performance. Salidroside and tyrosol have been well separated within 6 min in a 40 cm long capillary at a separation voltage of 12 kV using a 50 mM borate buffer (pH 9.8). The prepared graphene‐based CE detector offered significantly lower detection potential, yielded enhanced signal‐to‐noise characteristics, and exhibited high resistance to surface fouling and enhanced stability. It showed long‐term stability and reproducibility with relative standard deviations of less than 5% for the peak current (n=15).

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