SULPHATE TUBE TEST
The Sulphate tube test is used to detect the presence of Sulphate reducing micro-organisms in:
The Sulphate Reducing Bacteria (SRB) tube test is designed to assess the contamination of water samples with sulphate reducing bacteria. The test contains a straw coloured medium which reacts to the production of hydrogen sulphide to give a semi-quantitative result after 5 days.
The SRB test is used specifically to indicate the presence of bacteria, which under the correct conditions, are able to produce hydrogen sulphide. Hydrogen sulphide is a colourless gas which is extremely corrosive to ferrous and no ferrous metals. This can lead to holes in water systems and leaks in tankers by dissolving the surrounding metal.
Metal surfaces which are prone to attack by SRB can also be tested. A swab can be used to swab surfaces or corrosion pits and the swab is then thrust into a Sulphide test tube.
The test consists of a screw capped, glass tube half filled with a selective microbiological culture medium that semi-quantitatively indicates the presence of sulphide generating bacteria by the rate and extent of the development of a black colour. Sample is added to the tube which is kept warm (incubated) for up to seven days; results are examined regularly.
Results are determined by the spreading black precipitation from the inoculation point though the agar. When testing samples already high in sulphide there may be a sudden blackening and of the medium, in which case, contamination can be judged by the advancement of the blackening further into the medium.
The test has been calibrated against the standard Test Method for SRB, NACE TMO-194-94, using American Petroleum Institute (API) Medium.
Download the technical date sheet here.
TUBE TEST CODES