Preparation of Quality Control Material for Assuring Quality of Electrical Conductivity Measurements in Soil

Tahoun, Ibrahim Farag; Shehata, Adel; Nasr, Randa

doi:10.21608/ejchem.2018.3005.1254

Preparation of Quality Control Material for Assuring Quality of Electrical Conductivity Measurements in Soil

Document Type : Original Article

Authors

¹ National Institute of Standards, Tersa St, El-Matbah, Haram, P. O. Box: 136 Giza, Code No: 12211 Giza, Egypt

² National Institute of Standards, Tersa St, El-Matbah, Haram, P. O. Box: 136, Code No: 12211 Giza, Egypt

10.21608/ejchem.2018.3005.1254

Abstract

Accurate and reliable analytical results of soil have become essential tool for understanding salinity and limiting factors affecting agricultural productivity. Reliability of results depends mainly on the existence and quality of reference materials which are considered as crucial tools for validation and verification of the analytical process and assuring quality of measurement results. The National Metrology Institute of Egypt [NIS] is striving to set up the national standards to ensure all measurement results are traceable to the international system of unit (SI). NIS starting development of a series of soil reference materials to meet Egyptian requirements and customer demands. This article describes the production process of the soil reference material characterized for electrical conductivity from processing to value assignment. Characterization, homogeneity and stability studies of the material were carried out according to ISO guides 34, 35 and 80. The measurement results were statistically analyzed to calculate assigned values. The assigned value and expanded uncertainty for EC1:1 and EC1:5 methods were found 1234 ±58 µS/cm and 973 ±52 µS/cm, respectively.

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