| Abstract: | Abstract A carbon paste electrode modified with cobalt phthalocyanine (CPECoPc) was developed and applied to the determination of hydrazine [N2H4] in industrial boiler feed water. The CPECoPc exhibited good electrocatalytical activity for hydrazine oxidation at pH 13. A linear correlation was obtained between anodic peak current (Iap) and hydrazine concentration in the range of 1.25 × 10?4 to 9.80 × 10?4 mol L?1, fit by the equation Iap = 1.47 + 4.90 × 105 [N2H4] with a correlation coefficient of 0.9967. A detection limit of 7.35 × 10?5 mol L?1 was obtained. Recovery of hydrazine from three samples ranged between 99.0% and 102.9%. The modified electrode showed no interference by cations commonly present in boiler water, such as K+, Na+, Ca2+, Mg2+, Al3+, Pb2+, and Zn2+. The results obtained for hydrazine in boiler water using the proposed modified electrode are in agreement with the data obtained by a standard spectrophotometric method, at the 95% confidence level. |
