Electrochemical Determination of Caffeine Content in Ethiopian Coffee Samples Using Lignin Modified Glassy Carbon Electrode

Figure 2

Cyclic voltammograms of lignin modified GCE at pH 5 ABS containing 1 mM caffeine at different scan rates ((a)–(m): 10, 20, 40, 60, 80, 100, 125, 150, 200, 250, 300, 350, and 400 mV s⁻¹, resp.). Inset: plot of oxidative peak current as a function of the square root of scan rate.