1.1 This standard is applicable to determination of hydrogen chloride in the organized and fugitive emissions of stationary sources.
1.2 In the analysis of fugitive emission samples, when the sampling gas volume is 60L, the detection limit of hydrogen chloride is 0.05mg/m3, and the concentration range for quantitative determination is 0.16mg/m3~0.80mg/m3; in the analysis of organized emission samples, when the sampling gas volume is 10L, the detection limit of hydrogen chloride is 0.9mg/m3, and the concentration range for quantitative determination is 3.0mg/m3~24mg/m3.
1.3 Under the color development conditions specified in this standard, when the sampling gas volume is 100L, the concentration of hydrogen fluoride (HF) is higher than 0.2 mg/m3, that of hydrogen sulfide (H2S) is higher than 0.1 mg/m3, or that of hydrogen cyanide (HCN) is higher than 0.1 mg/m3, the determination of hydrogen chloride will be interfered.
2 Theory
Hydrogen chloride (HCl) is absorbed by dilute sodium hydroxide solution. The chloride ion in the absorption solution reacts with mercury thiocyanate to generate mercury bichloride molecules which are difficult to ionize, and the replaced thiocyanate reacts with ferric ions to generate orange-red ferric thiocyanate complex ions, which are determined by spectrophotometric method according to color depth. The reaction equation is:
3 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard.
GB 16297-1996 Comprehensive emission standard of air pollutants
GB 16157-1996 The determination of particulates and sampling methods of gaseous pollutants emitted from exhaust gas of stationary source
