[Berberine-electrochemical detector for the determination of berberine-type alkaloids in various Chinese patent medicines by flow injection analysis].

A description is given for the preparation of flow through sensor and of the incorporation of the sensor into a flow injection analysis system. The parameters affecting the measurement are discussed. An accurate, convenient and rapid method is proposed for the determination of berberine-type alkaloids in various Chinese patent medicines (Coptis chinensis Franch., Phellodendron chinesis Schneid., xianglian wan, zuojin wan, ermiao wan and sanmiao wan). The slope is 54-60 mV/decade over the concentration range of 10(-3)-3 x 10(-6) mol/L berberine at pH 2-9.5. Direct potentiometry determination of berberine in various samples showed an average recovery of 99.5-103.5% and a relative standard deviation of 1.3-3.5% at a sampling rate of 120/h.