ASTM D7773-12 Determination of Volatile Inorganic Acids

Scope:

Inorganic acids in the workplace can cause skin, eye, and respiratory tract irritations. There are exposure limits for hydrochloric acid, hydrobromic acid, and nitric acid in the air that have been established to limit the danger exposure to workers who may be affected. Analytical and sampling techniques are needed for exposure and volatile inorganic acids for risk assessment and mitigation objectives.

Procedure:

To gather volatile inorganic acids, a known volume of air is pulled through a pre-filter, and an alkali-impregnated quartz fiber filter is installed in an inhalable sampler. The acids are collected on the impregnated quartz fiber filter. Extracting the acids collected on the sample filter to solubilize the analytes of interest, water or eluent is used. Ionization of the sample solution is performed on aliquots. Chromatography is used on additional anions, such as nitrate or bromide, to separate the extracted chloride. As a result, the anions are separated and measured using a conductivity or density meter.

Result:
The results are plotted on the UV-vis detector, and the analytical results are a function of the measured conductivity or absorbance concentration.