Sulphur Species
Compounds that contain sulphur that are typically
tested for include:
- Sulphur dioxide (SO2)
- Sulphuric Acid Mist (H2SO4)
- Sulphur Trioxide (SO3)
- Hydrogen Sulphide
- Reduced Sulphurs (hydrogen sulphide, carbonyl sulphide COS,
methyl mercaptan, ethyl mercaptan, dimethyldisulphide, carbon
disulphide)
Methods
Sulphur dioxide, Sulphuric Acid Mist
and Sulphur Trioxide (USEPA Method 8)
Sulphur dioxide, sulphuric acid mist and sulphur trioxide are
sampled using USEPA method 8. The SO3/acid mist are captured in
impingers with isopropyl alcohol. After the gas has passed through
impingers with isopropyl alcohol it passes through impingers with
peroxide in it. These will capture any sulphur dioxide.
The resulting solutions are analysed by titration with barium
chloride using a thorin indicator.
Total Reduced Sulphur (TRS) USEPA Method 16
The method used to determine TRS is USEPA method 16. All of the
reduced sulphur species are sampled and analysed together. The gas
sampled intially passes through teflon impingers with a citrate
buffer. This removes the sulphur dioxide.
The gas then passes through a tube furnace which is heated to 800
C. This converts the reduced sulphur gases to sulphur dioxide where
it is subsequently captured by impingers with hydrogen peroxide
in them.
The completed sample train is then validated by introducing calibrated
gas of a known concentration to determine how efficient the train
is in capturing known concentration gas.
All samples are analysed by titration with barium chloride and
thorin indicator.
|
