ISO 11423-1:1997
Water quality -- Determination of benzene and some derivatives -- Part 1: Head-space gas chromatographic method
http://www.doc88.com/p-9085324109537.html
ISO 11423-2:1997
Water quality -- Determination of benzene and some derivatives -- Part 2: Method using extraction and gas chromatography
http://www.doc88.com/p-7734452600908.html