{Reference Type}: Journal Article
{Title}: Rigorous pH measurement in non-aqueous solution: measurement method and reference values in ethanol.
{Author}: Bastkowski F;Heering A;Uysal E;Liv L;Leito I;Quendera R;Ribeiro L;Deleebeeck L;Snedden A;Nagy D;Szilágyi ZN;Camões F;Anes B;Roziková M;Stoica D;
{Journal}: Anal Bioanal Chem
{Volume}: 416
{Issue}: 2
{Year}: 2024 Jan 25
{Factor}: 4.478
{DOI}: 10.1007/s00216-023-05043-5
{Abstract}: The recently introduced unified pH ([Formula: see text]) concept enables rigorous pH measurements in non-aqueous and mixed media while at the same time maintaining comparability to the conventional aqueous pH scale. However, its practical application is hindered by a shortage of reference [Formula: see text] values. In order to improve this situation, the European Metrology Research Project (EMPIR) UnipHied ("Realisation of a UnipHied pH scale") launched an interlaboratory comparison among highly experienced electrochemistry expert laboratories to assign the first such reference [Formula: see text] values by adopting an extensive statistical treatment of the reported measurement data: to phosphate buffer in water-ethanol mixture (50 wt% of ethanol) and ammonium formate buffer in pure ethanol. Two different measurement setups - one capable of being easily adopted in industrial applications - have been used to demonstrate the robustness of [Formula: see text] measurement. This is an important step towards wider adoption of the [Formula: see text] concept in practice, like liquid chromatography, biofuels analysis and electrocatalysis.