LaMotte DC1600 Colorimeter - Manual (Page 81)

SULFATE
BARIUM CHLORIDE METHOD CODE 3665
QUANTITY CONTENTS CODE
10 g *Sulfate Reagent *V-6277-D
1 Spoon, 0.1 g, plastic 0699
*WARNING: Reagents marked with a * are considered hazardous substances. Material Safety Data Sheets (MSDS) are supplied for
these reagents. For your safety, read label and accompanying MSDS before using.
The most common mineral forms of sulfur are iron sulfide, lead sulfide, zinc sulfide and as calcium sulfate and magnesium
sulfate. In most fresh waters the sulfate ion is the second or third most abundant anion, being exceeded only by bicarbonate
and, in some cases, silicate. Sulfur, in the form of sulfate, is considered an important nutrient element. Mineral springs are
rich in sulfate and feed appreciable quantities of this compound to the watershed. Acid mine water drainage is a form of
pollution which may contribute extremely large amounts of sulfate content to natural waters. Other sources of sulfate
include waste material from pulp mills, steel mills, food processing operations and municipal wastes. Many bacteria obtain
sulfur from sulfate for the synthesis of amino acids. In lakes and streams low in oxygen, this process of sulfate reduction
causes the production of hydrogen sulfide, with its characteristic offensive odor. Calcium sulfate and magnesium sulfate
contribute significantly to the hardness of water. Under natural conditions, the quantities ordinarily to be expected in lakes
are between 3 and 30 parts per million.
APPLICATION: Drinking and surface waters, domestic and industrial wastes.
RANGE: 0 – 100 ppm Sulfate
METHOD: Sulfate ion is precipitated in an acid medium with barium chloride to form a barium sulfate
suspension in proportion to the amount of sulfate present.
SAMPLE HANDLING
& PRESERVATION: Sulfate samples may be preserved by refrigeration at 4°C up to 7 days in glass or plastic
containers without any change in concentration.
INTERFERENCE: Suspended matter and color interference may be removed by a filtration step. Silica in excess
of 500 mg/L will interfere.
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