This standard describes a manual method for determining the mass concentration of total gaseous mercury (TGM). The method does not distinguish between elemental, inorganic or organic mercury. Because of the low mass concentrations of TGM, an enrichment sampling method is used. For the determination of TGM the air is sucked through glass tubes with an amalgamation trap or a glass tube containing a mix catalysator as a sorbent. The particle-bound mercury is retained by an upstream filter. The analytical determination is performed by thermal desorption of the mercury, amalgamation and subsequent analysis by atomic absorption spectrometry (AAS) or atomic fluorescence spectrometry (AFS). The method is suitable for the determination of weekly to monthly mean values. In addition, a manual procedure for the determination of particle-bound mercury after filter sampling in ambient air is described in an Annex. The final standard will replace the standards VDI 2267 Part 8:2000-03 and Part 9:2002-07.