2.3.2. GC–MS measurements of volatile amines in concrete samples
Each building material sample (471 g) was shaken with 10 mL
of 1 M HCl for 1 min. After sedimentation of the suspension the
aqueous supernatant was aspirated into a 5 mL syringe. Then
0.5 mL of this solution was filtered through a syringe filter and
analyzed by the GC–MS system. The GC was fitted with an RTX-5
MS capillary column (5% diphenyl and 94% dimethyl polysiloxane,
30 m 0.25 mm i.d., 0.25 μm coating). The injector temperature
was kept at 220 °C while the interface temperature and the ion
source were at 200 °C. Helium was used as the carrier gas at a flow
rate of 2 mL min1
. A sample volume of 1 μL was injected in
splitless mode with 1 min of purge time. The electron ionization
source was run at 70 eV. For identification of volatile amines,
library search was carried out using NIST, NBS and Wiley GC–MS
libraries.