Journal of Analytical Methods in Chemistry / 2014 / Article / Tab 5

Research Article

A Modified o-Phthalaldehyde Fluorometric Analytical Method for Ultratrace Ammonium in Natural Waters Using EDTA-NaOH as Buffer

Table 5

Analytical results of the proposed method and classical OPA method.

Seawater sampleThe proposed method (mol/L)The classical OPA method (mol/L)Calculated -valueCritical -value ( = 0.05)

10.536 ± 0.008 ( = 4)0.560 ± 0.018 ( = 4)2.432.45
20.385 ± 0.006 ( = 3)0.360 ± 0.035 ( = 3)1.222.78