| 摘要 |
PURPOSE:To make possible the exact and automatic quantitative determination of the concn. of trace calcium with a simple operation by adding an adequate masking agent to a sample soln. and utilizing a blank soln. with which the calcium-component is hardly detectable. CONSTITUTION:The sample soln. added at least with the masking agent for masking the calcium is used as a blank soln. and the quantitative determination of the trace calcium in an aq. soln. is executed in a colorimetric spectrochemical analysis method of the calcium. An ordinary chelate reagent to be used as a titrating reagent for chelate titration, for example, ethylenediaminetetraacetic acid is used for the masking agent. An ordinary colorimetric spectrochemical analysis method is used for the quantitative determination method. The aq. soln. contg. calcium ion is prepd. as the sample liquid and alizarin acid black SN is added as a color forming agent into the test liquid. Such liquid added with the masking agent is subjected as the blank soln. to colorimetry. Since the backgrounds of both the sample liquid and the blank soln. are commonly used, the errors by the liquid nature of the sample liquid are offset. |
