Alkali Metal Salt Interference on the Salicylate Method for Quantifying Ammonia from Nitrogen Reduction

Abstract

The salicylate method has been extensively used for quantifying ammonia in the emerging field of nitrogen (electro)fixation. Alkali metal salts are widely used as supporting electrolytes for nitrogen reduction, especially in the context of electrochemical nitrogen fixation. However, these salts are known to cause interferences on the salicylate method, introducing significant uncertainties in ammonia quantification. In this work, the interference of lithium, sodium and potassium chlorides, perchlorates and sulfates on the ammonia quantification results obtained using the salicylate method was experimentally quantified, and an empirical model was developed to capture the effect of the presence of these interferents on the ammonia quantification by the salicylate method. Based on the obtained experimental interference results, the tested interferents can be ranked from stronger interferent (i.e. lower admissible concentration) to weaker interferent: Li2SO4, KClO4, LiCl, LiClO4, K2SO4, NaClO4, NaCl, Na2SO4, KCl. The developed model can be used to assess the experimental error in ammonia quantification from nitrogen reduction, in samples containing these interferents. This model can be used to correct the interferences on the ammonia quantification, when the interferent concentration in a sample is known (or measurable).

Refining the Spectroscopic Detection Technique: A Pivot in the Electrochemical Ammonia Synthesis

“…Gradually, research interests started to incline and focus on the detection methods and the fallacies related to the techniques came to the fore suggesting a need for the proper roadmap toward spectroscopic ammonia detection. Although two recent reports by Shao-Horn et al, optimized the salicylate method thoroughly, , the Indophenol method still demands a deep understanding and optimization. It is extremely vital to perceive the role of each of the coloring agents and the underlying mechanism for each of the reaction steps in order to set up optimum conditions that would influence the ultimate formation of the indophenol dye, as shown in Figure about the aim of this work.…”

“…But interference of these salts in the detection methods adds to the uncertainties in the quantification of ammonia. While Shao-Horn et al has accounted for a series of alkali metal salts and have ranked them based on their interfering properties in the salicylate method of ammonia detection, here in this work, we intended to particularly look into the effect of alkali metal ions (Li + , Na + , and K + ) and the anion counterparts like (OH – , Cl – , ClO 4 – , SO 4 2– , and PO 4 3– ) on the indophenol method of ammonia detection. For checking the role of cations, we had stuck to Cl – as the anion and for the effect of anions, H + was considered as the constant cation and all the concentrations were maintained as 0.1 M as conventionally used in literature .…”

“…But interference of these salts in the detection methods adds to the uncertainties in the quantification of ammonia. While Shao-Horn et al has accounted for a series of alkali metal salts and have ranked them based on their interfering properties in the salicylate method of ammonia detection, 29 here in this work, we intended to particularly look into the effect of alkali metal ions (Li + , Na + , and K + ) and the anion counterparts like (OH − , Cl − , ClO…”

Growth performance and nutritional composition of Clarias gariepinus in flood-and-drain aquaponics coupled with three species of leafy vegetable

“…The total dissolved solutes (TDS) and pH of the water were measured weekly using a handheld digital API Master TDS and pH monitor. The concentration of non-ionized ammonia in the collected water samples was determined by the salicylate method(Giner-Sanz et al, 2022), nitrite concentration by the diazotization method (el hani et al, 2022) and nitrate concentration by the Szechrome NAS reagent (Taylor et al, 2010).…”

Lithium‐Mediated Nitrogen Reduction for Ammonia Synthesis: Reviewing the Gap between Continuous Electrolytic Cells and Stepwise Processes through Galvanic Li─N2 Cells

“…[ 47 ] Moreover, a further study from the same group pointed out the interference of alkali metal salt on the colorimetric chemicals. [ 48 ]…”