. "1" . "1" . "SDN:P07::CF12N218" . "2009-07-06 15:41:29.0" . . . "accepted"@en . "" . . "mass_concentration_of_ammonia_in_air"@en . . . "false" . . . "SDN:P07::CF12N218" . "Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ammonia is NH3."@en . . "2009-07-06 15:41:29.0" . "SDN:P07::CF12N218" .