Abstract
A novel method for the determination of dissolved inorganic nitrite and nitrate in surface seawater was reported, which is based on the diazotization reaction between nitrite and a novel red-region fluorescent dye, tetra-substituted amino aluminum phthalocyanine (TAAlPc). Nitrate is determined as nitrite after reduction on a cadmium column. Under optimal conditions, the linear range of the calibration curve is 21–840 nM for nitrite. The detection limit is 7 nM for and the relative standard deviation for six replicate measurements of a 350 nM nitrite solution is 3.2%. Since the method employs a red-region fluorescent dye (λex/em = 610 nm/678 nm), the potential fluorescent background resulting from the organic matters in seawater can be eliminated and thus the sensitivity of the method can be enhanced.
ACKNOWLEDGMENT
The financial support of the National Natural Science Foundation of China (No. 29775021) is gratefully acknowledged.