Certification of the deuterium distribution in ethanol from grape, sugar cane and sugar beet sugars' fermentation : ERM®-AE200 : certification report

ERM-AE200 is a set of three ethanol materials certified for the deuterium (D) distribution (deuterium-tohydrogen (D/H) amount of substance ratios and the relative deuterium-to-hydrogen ratio), produced within the scope of ISO 17034 accreditation [1] and ISO Guide 35:2017 [2]. The certified reference material (CRM) comprises three NMR tubes, each containing at least 4.65 ml of a solution combining ethanol (from grape, sugar cane or sugar beet), tetramethylurea and hexafluorobenzene. The tubes are sealed under an atmosphere of argon. Between-unit homogeneity was quantified and stability during transport and storage was assessed in accordance with ISO Guide 35:2017 [2]. The material, contained in sealed NMR tubes, is intended for direct measurement of the intact tube with SNIF-NMR, a non-destructible analysis. Therefore, the minimum sample size for one measurement is the full content of the NMR tube and repeated use is possible. The material was characterised by an interlaboratory comparison of laboratories of demonstrated competence and adhering to ISO/IEC 17025:2017 [3]. All results were technically valid and no outlier was eliminated unless a technical reason for the deviation was found. Uncertainties of the certified values were calculated in accordance with ISO 17034:2016 [1] and ISO Guide 35:2017 [2] and include uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for the performance verification of NMR spectrometers in SNIF-NMR measurements. As with any reference material, it can be used for establishing control charts. Before release of the ERM-A200, the certification project was subjected to peer-review involving both internal and external experts.