Development of certified reference material of mineral composition of natural water designed to control of turbidity measurement accuracy

• Main Authors: Liudmila I. Gorjaeva, Elena L. Lebedeva
• Format: Article
• Language: Russian
• Published: Ural Research Institute of Metrology 2017-06-01
• Series: Standartnye Obrazcy
• Subjects: мутность; нитрат; фторид; хлорид; общее железо; вода природная; формазин; турбидиметрия; стандартный образец; turbidity; nitrate; fluoride; chloride; total iron; natural water; formazine; turbidimetry; certified reference material
• Online Access: https://www.rmjournal.ru/jour/article/view/118

Introduction. The results of development of a certified reference material (CRM) of mineral composition of natural water are presented. A solution prepared from the material of the CRM specimen imitates mineral composition of natural surface water. The certified values are mass fractions of nitrate ions, chloride ions, fluoride ions, and total iron and turbidity according to formazine scale. Materials and methods. The certified values of mass concentrations of the components were determined using calculated experimental evaluation procedure;the certified turbidity value was determinedusing the certified turbidimetric method. Results. The relative expanded uncertainty (k = 2) of the certified turbidity values does not exceed 5 %, the same value for mass concentrationsis not more than 3.5 %. Relative standard uncertainty from heterogeneity does not exceed 1.0 %. The shelf life of the developed CRM is set to 3 years. Discussion and conclusion. Developed CRM was registered in the State Register of CRM's as GSO 10815-2016. The CRM is designed to control the accuracy of results of the certified characteristics measurements, including proficiency testing of laboratories using interlaboratory comparative tests. The CRM can be used for validation of measurement procedures.