Laboratory dust arsenic

Wear nitrile rubber gloves, eye protection, and laboratory coat. Avoid breathing dust. In the fume hood, dissolve the arsenic compound in acidified boiling water (for 1 g of arsenic compound, use 100 mL of water containing 6 drops of concentrated hydrochloric acid). Add a solution of thioacetamide (for each 1 g of arsenic salt, use 0.2 g of thioacetamide in 20 mL of water). Boil the mixture for 20 minutes and then basify with 2 M sodium hydroxide (prepared by dissolving 8 g of NaOH in 100 mL of water). Filter the precipitate, dry, and package for disposal in a secure landfill site. ... 

Rates of emission of SO2, HCl, NOx (nitrogen oxides) and hydrocarbons are measured at the stack and recorded continuously by a computerized data aquisition system in the central operation control room. Dust particles, which may contain residual arsenic, for example, are separated isokinetically from the off-gas by a dust probe and subjected to laboratory analysis by atomic absorption spectroscopy. 

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