YSI 9300 Photometer - Manual (Page 98)

PHOTOMETER TEST INSTRUCTIONS
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Natural waters containing dissolved hydrogen sulfide and other sulfides are
found in certain parts of the world, particularly in areas having hot springs. Sul-
fides are constituents of many industrial wastes such as those from tanneries,
gas plants and chemical works. Sulfides can be toxic to fish and aquatic life; and
their presence in water supplies gives rise to undesirable tastes and odours.
The YSI Sulfide Test provides a simple method of measuring total available
sulphide over the range 0 - 0.5 mg/l and is particularly applicable to natural and
drinking waters. Higher levels, such as those found in effluents and waste waters,
can be determined by diluting the sample.
Method
This simplified method for the determination of sulphide is based on a reagent
containing diethyl-p-phenylene diamine (DPD) and potassium dichromate. Sul-
fide reacts with this reagent in acid solution to produce a blue colored complex.
In the absence of sulphide the reagent produces a pink color. Chlorine, and
other oxidizing agents which normally react with DPD, do not interfere with the
test. The reagents are provided in the form of two tablets and the test is simply
carried out by adding one of each tablet to a sample of the water.
The color produced is indicative of the sulphide concentration and is measured
using a YSI Photometer.
Reagents and Equipment
YSI Sulfide No 1 Tablets
YSI Sulfide No 2 Tablets
YSI 9300 or 9500 Photometer
Round Test Tubes, 10 ml glass (PT 595)
Photometer Method
AUTOMATIC
WAVELENGTH
SELECTION
0 – 0.5 mg/l
PHOT.33.AUTO