Salinity determinations by refractometry and oscillation-type densimetry as compatible methods: From salinity to pH

Abstract

The purpose of the present communication is to study the metrological compatibility of measurement results of mass fractions of sodium chloride in aqueous solutions, by different analytical techniques: refractometry and oscillation-type densimetry. In complement pH measurements were made in solutions of NaCl of 3,5 cg g-1 and in a synthetic seawater standard (OSIL). Previously, metrological compatibility of measurement results with refractometer and oscillation-type density meter was showed for aqueous solutions of glucose, from 2 cg g-1 to 42 cg g-1. Due to its interest for the food science and health science, sodium chloride mass fraction in aqueous solution between 0,5 cg g-1 and 7 cg g-1 and for brine systems were also measured. Comparison was displayed between potentiometric pH and pH deduced by salinity experimental value.