Key development stages of reference material for lactose monohydrate composition

Abstract

The article mirrors key stages of development of reference material (RM) for the composition of lactose monohydrate with certified values of mass fraction of water and basic material. The RM could be used in the analytical chemistry and food industry, as well as at identification and assessment of nutritive products safety, int. al., infant food. The RM under development will be intended for metrological assurance of mass fraction of water and basic substance measuring instruments based on usage of thermogravimetric, titrimetric and chromatographic methods, certification of measurement procedures and control of measurement results of lactose monohydrate mass fraction accuracy, used as the host material, and in compositions of organic substances and materials or in measurements of water mass fraction in solid substances and materials, as well as for other kinds of metrological control. Determination of certified value of lactose monohydrate mass fraction in the RM was performed by reference method of iodometric titration and affirmed by mass balance method (one hundred minus the number of impurities) and by calculating-experimental method. The certified value of mass fraction of water was assigned by the Fischer’s method of volumetric titration and confirmed by the thermogravimetric method. Considerable attention was focused to the study of the separation process of sorbed and crystallisation water in a high-purity lactose monohydrate reagent. The results of measurements of the quantitative content of the types of water were considered when assessing the purity of the target substance by various methods. Unlike existing RM of similar composition, the traceability of the certified values of the RM being developed will be ensured to units of values reproduced respectively by the state primary (GET 173-2017) and secondary (GVET 176-1-2010) standards.