Jump to main content
Jump to site search

Issue 5, 2013
Previous Article Next Article

An optimized bioluminescent assay for inorganic sulfate quantitation in freshwater

Author affiliations

Abstract

In this paper an optimized enzymatic assay for inorganic sulfate (SO−24) detection and quantitation in freshwater, relying on adenosine-5′-triphosphate sulfurylase catalyzed reaction coupled to bioluminescent detection by firefly luciferase, is described. Inorganic sulfate is converted, by adenosine-5′-triphosphate sulfurylase, into adenosine-5′-phosphosulfate and inorganic pyrophosphate, with consumption of adenosine-5′-triphosphate. The remaining adenosine-5′-triphosphate is used as a co-factor in the reaction catalyzed by firefly luciferase generating, as a co-product, photons of visible light. The light output is inversely proportional to the inorganic sulfate content. Using sodium sulfate as a model, the assay was optimized through a statistical experimental design methodology and validated in water samples from domestic wells from two municipalities within the Metropolitan Area of Porto plus tap water as control. The optimized method requires 20 μL of sample in a final reaction volume of 100 μL. It is linear in the range from 14 to 134 mg L−1 of inorganic sulfate, with limits of detection and quantitation of 10 and 34 mg L−1, respectively. Repeatability, expressed as relative standard deviation, is 7.23% at 34 mg L−1, 6.87% at 68 mg L−1 and 4.67% at 96 mg L−1. The inorganic sulfate concentration in the wells is approximately 124, 182 and 182 mg L−1, whereas it was found to be a value of about 200 mg L−1 in tap water. Samples can be quantified by calibration curves without any pre-treatment other than dilution. The optimized method is fast, simple to perform and robust.

Graphical abstract: An optimized bioluminescent assay for inorganic sulfate quantitation in freshwater

Back to tab navigation

Supplementary files

Publication details

The article was received on 23 Oct 2012, accepted on 09 Jan 2013 and first published on 10 Jan 2013


Article type: Paper
DOI: 10.1039/C3AY26255C
Citation: Anal. Methods, 2013,5, 1317-1327
  •   Request permissions

    An optimized bioluminescent assay for inorganic sulfate quantitation in freshwater

    S. M. Marques and J. C. G. Esteves da Silva, Anal. Methods, 2013, 5, 1317
    DOI: 10.1039/C3AY26255C

Search articles by author

Spotlight

Advertisements