Under the recommended conditions (pH 2.0, B-R buffer, at a reduction potential of -489 mV and -50 mV pulse amplitude, and 1 second drop time ), the consecutive additions of CA (Fig. 2) gives a linear relationship between the peak currents and concentrations in the range of 1-90 uM with the linear regression equation given by: Ip/uA = 0.003 C/uM + 0.004 (Rกำลัง2 = 0.994) (n = 14).