Optimization of the salicylate method for ammonia quantification from nitrogen electroreduction

•The salicylate method was optimized for aqueous and non-aqueous samples.•The factors that affect the quantification results were identified.•The proposed methods exhibit a good reproducibility for a given reagent brand.•The detailed experimental procedures are included in this work. The salicylate method is one of the colorimetric methods that is used for ammonia quantification in nitrogen (electro)fixation. While the salicylate method offers advantages in that it avoids working with toxic reagents and does not generate toxic fumes, ammonia quantification is sensitive to the exact experimental conditions (e.g. color development time, exposure to light, etc.) and to a number of interferences (e.g. pH of the samples, presence of interferents, etc.), which leads to reproducibility problems. In this work, the influence of different factors on the ammonia quantification in Nitrogen Reaction Reduction (NRR) using the salicylate method was examined, both in aqueous media and in non-aqueous media. The detailed experimental procedures presented in this work, provide an optimized reference method for quantifying ammonia in NRR screening experiments using the salicylate method.