1.1 ,This on-line test method includes hydrogen exchange and degassing by heating or gas stripping and provides means for determining anions (such as Cl^−,, SO₄^—,, NO₃^−,, and F^−,) at levels as low as 2 μ,g/L (2 ppb) and carbon dioxide at the level of 0.01 to 10 mg/L (ppm) at 25°,C in high purity water and in steam and water samples in power plants by measuring electrical conductivity.