Simple Methods for Sensitive Spectrophotometric and Spectrofluorometric Determination of Nitrite using 1-aminoanthraquinone and 1,4-diaminoanthraquinone

Abstract

Highly sensitive spectrophotometric and spectrofluorometric methods have been proposed for determination of trace amount of nitrite in water samples. The methods are commonly based on mixing an organic phase containing 1-aminoanthraquinone (1-AAQ) or 1,4-diaminoanthraquinone (1,4-DAAQ) with an aqueous acidic solution of nitrite. By diazoation of the aminoanthraquinone (AAQ) content, the absorbance decreasing or luminescence quenching of the organic phase is relevant to the nitrite concentration. The reactions conditions and other important analytical parameters were optimized to enhance the sensitivity of the methods. Interference if any, by non-target ions was also investigated. No considerable interference was observed due to the presence of coexisting anions and cations. The proposed methods were successfully applied for determining nitrite in environmental samples.

Key Words:

• aminoanthraquinone
• nitrite determination
• spectrophotometry
• spectrofluorometry