公开(公告)号：JPH05240831A

公开(公告)日：1993-09-21

申请号：JP7833292

申请日：1992-02-28

Applicant: TOA ELECTRONICS ,  NIKKISO CO LTD

Inventor： AIZAWA MUTSUO ,  YAMADA KOJI ,  NAKAO KATSUHISA

IPC: G01N27/416 ,  G01N27/48

Abstract: PURPOSE:To measuer the amount of hydrazine in test water accurately without the obstruction of metal ions and to make it possible to perform the stable measurement for a long period by using a polarographic oxidation-reduction current method even if reducing ions such as Fe (II) and the like are present in the test water. CONSTITUTION:In a mixing device 2 of a measuring apparatus, test water from a test-water regulating cell FS1 and electrolyte, wherein EDTA from an electrolyte container 4 is added, are mixed. The EDTA is added into the test water. The test water is injected into a measuring cell 1, wherein a working electrode WE, a counter electrode CE and a comparing electrode RE are provided. The amount of the hydrazine in the test water is measured by a polarographic oxidation-reduction current method. The reducing metal ions such as Fe (II) and the like are masked by the addition of the EDTA. Therefore, the amount of the hydrazine of the test water can be accurately measured without the blocking of the metal ions. Since the metal ions are not attached to the electrodes, deterioration does not occur, and the measurement can be performed stably for a long period.

公开(公告)号：JPH0341354A

公开(公告)日：1991-02-21

申请号：JP17740889

申请日：1989-07-10

Applicant: TOA ELECTRONICS

Inventor： YAMADA KOJI ,  MINAMIMOTO ITARU ,  AIZAWA MUTSUO ,  NAKAYAMA MASARU

IPC: G01N27/416

Abstract: PURPOSE:To simply measure high concn. hydrazine with good reproducibility by a method wherein potassium nitrate or potassium chloride is added to and mixed with water to be examined containing hydrazine to be measured in a specific ratio. CONSTITUTION:Potassium nitrate or potassium chloride is added to water to be examined containing hydrazine to be measured in an amount of 0.012 mol/l or more to be uniformly mixed therewith by a mixer 8 and the redox current of hydrazine is measured with respect to the water to be examined. That is, KCl or KNO3 is preliminarily added to the water to be examined guided from boiler water to be examined guided from boiler water as a support electrolyte to be uniformly mixed therewith by the mixer 8 and contained up to the high concn. corresponding to the concn. of hydrazine being a limit capable of being usually contained in boiler water and, therefore, the linearity of the concn. of hydrazine and a current value is obtained from a low concn. range of about 0 - 20 ppb of hydrazine to a high concn. range of about 10 ppm and hydrazine can be measured with good reproducibility.