EM Quant® Sulfate Test, Catalog No. 10019
Test strips and reagent for the detection
and semi-quantitative determination of sulfate ions
The Sulfate Test is a rapid exploratory test. It
can be used togive a rough estimation of the sulfate ion content of
drinking and industrial water, as well as of effluent discharged, for
instance, from electroplating works and leathergoods manufacturers.
Pollutedground and surface waters may contain 300 or more mg of
sulfate per liter.
Principle of the Method
The four reaction zones sealed on to the strip
contain different amounts of red thorin barium complex. The strips
progressively turn yellow when the right concentration (of sulfate
ions) is present.
0 - 400 - 800 - 1200 - 1600mg/l (ppm) SO42–.
- Immerse a test strip in the sample solution
(not running water) for 1 second so that all four reaction zones are
- Remove the test strip,gently shake off any
surplus liquid, wait 2 minutes and compare the reaction zones with
the color scale.
The sample solution should have a pH of between
4 and 8. Acidic solutions (pH <4) must be buffered with sodium
acetate. Alkaline solutions (pH >8) must be adjusted by adding
ascorbic acid or tartaric acid.
Evaluating the color change
|Number of reaction zones for light red
||Number of reaction zones for yellow
|Color change within the range mg/l (ppm)
The color changes from light red to yellow
within the ranges listed. If the test solution has a sulfate content
just at the upper limit of one of the color change ranges, the
reaction zone is still slightly red at both edges. At higher
concentrations the edges also turn yellow.
Aggressivity to Concrete
Several degrees of aggressivity are defined forground water depending on the amount of sulfate it contains.
200 - 600mg/l = slightly aggressive
600 -1600mg/l = strongly aggressive
above -3000mg/l = very strongly aggressive
Influence of Anions
The following ions can give a false positive reaction in which the reaction
zone turns orange:
|| >800mg/l ClO–3
|| >50mg/l CN–
|| >500mg/l S2O3–5
An interfering violet coloration due to MnO–4
can be eliminated by adding a few crystals of ascorbic acid to 5ml of
the solution and then shaking.
Influence of Cations
Interfering colorations that prevent the
detection of sulfate occur in the presence of the following ions:
>100mg/l Al3+ (orange-red)
>100mg/l Cr3+ (brown)
>10mg/l Cu2+ (orange-brown)
>100mg/l VO2+ (orange-brown)
These ions can easily be removed with Amberlite®
IR-120 ion exchanger. The ion exchanger must first be loaded with
sodium ions. Fill aglass column (2-4 cm in diameter) with 10g
Amberlite® IR-120 ion exchanger. Allow 50ml 1 mmol/l
hydrochloric acid, 100ml distilled water, 50ml 1 mol/l sodium
hydroxide solution to drip slowly through the column in the ordergiven followed by distilled water until a pH of 6-7 is obtained. Fill
aglass column (0.5-1 cm in diameter) with 2g of the prepared cation
exchanger and allow 10ml of the test solution, which should not
contain more than 2g/l of the cation to be separated to run through
slowly at a rate of approximately 1 drop/second. Test the eluate for
sulfate as described above.
10019 EM Quant® Pack of 100 test