Title: Verification of Utility of Simple Mensuration of Cl<sup>-</sup>from Urine to Estimate the Amount of Sodium Intake
Abstract: The purpose of this study was to measure concentrations of <TEX>$K^+$</TEX>, <TEX>$Na^+$</TEX>, <TEX>$Cl^-$</TEX> by ionometer with check salt strip, simple salimeter and Ion-selective electrode (ISE) and compare the results of each mensuration; furthermore, the possibility of inferring the <TEX>$Na^+$</TEX> concentration from <TEX>$Cl^-$</TEX> concentration of urine and the impact of <TEX>$K^+$</TEX> on the concentration of each ion was examined. The results showed that ISE determined <TEX>$Na^+$</TEX> and <TEX>$Cl^-$</TEX> concentrations in the urine are highly interrelated (R=0.9039); in addition, concentrations of <TEX>$Cl^-$</TEX>, measured with strip and ISE from urine are highly interrelated (R=0.9338). The concentration of <TEX>$Na^+$</TEX> in urine, inferred by measuring <TEX>$Cl^-$</TEX> concentration with strip, has a high relationship (R=0.8580) with the concentration of <TEX>$Na^+$</TEX> in urine, measured by ISE. The results of our study will increase awareness of <TEX>$Na^+$</TEX> intake and the utility of check salt strip, as well as the possibility of inferred <TEX>$Na^+$</TEX> concentration from measures of <TEX>$Cl^-$</TEX> concentration as a screening test for reducing sodium intake.