LaMotte SMART3 Colorimeter - Manual (Page 277)

SULFATE – HIGH RANGE
BARIUM CHLORIDE METHOD • CODE 3665-SC
QUANTITY CONTENTS CODE
10 g *Sulfate Reagent *V-6277-D
1 Spoon, 0.1 g, plastic 0699
*WARNING: Reagents marked with an * are considered to be potential health
hazards. To view or print a Material Safety Data Sheet (MSDS) for these reagents
go to www.lamotte.com. To obtain a printed copy, contact LaMotte by e-mail,
phone or fax.
The most common mineral forms of sulfur are iron sulfi de, lead sulfi de, zinc sulfi de
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
sulfi de, with its characteristic offensive odor. Calcium sulfate and magnesium
sulfate contribute signifi cantly 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
MDL: 3 ppm
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 fi ltration step. Silica in excess of 500 mg/L
will interfere. Check for stray light interference (see page
69).
SMART3 Test Procedures 11.10 SULFATE, High Range
Test P
rocedures