"1" . . "2009-07-06 15:41:29.0" . "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 butane is C4H10. Butane is a member of the group of hydrocarbons known as alkanes. There are standard names for the alkane group as well as for some of the individual species."@en . "accepted"@en . "1" . . . "SDN:P07::CF12N233" . "SDN:P07::CF12N233" . "false" . . . "mass_concentration_of_butane_in_air"@en . . "2009-07-06 15:41:29.0" . "SDN:P07::CF12N233" . . . "" .