LaMotte SMART Spectro Spectrophotometer - Manual (Page 100)

CHLORINE
LIQUID DPD METHOD • CODE 4859
QUANTITY CONTENTS CODE
30 mL DPD 1A Free Chlorine Reagent P-6740-G
30 mL *DPD 1B Free Chlorine Reagent *P-6741-G
30 mL *DPD 3 Total Chlorine Reagent *P-6743-G
*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.
All water for cities and communities must be sanitized; even waters that come from
clean sources, protected watersheds, reservoirs, and deep wells, are commonly
sanitized to assure safety. Chlorine is the most commonly used sanitizer for several
reasons: it is effective against a wide range of microorganisms, the cost is low, and
the methods of applying it have been well developed. If an adequate concentration
of chlorine is present in the water for a few minutes, disease producing bacteria
will be destroyed. A number of conditions affect the sanitizing action of chlorine. In
municipal systems these can be controlled so that if chlorine is detectable, it can
be assumed that bacteria have been killed. The factors that infl uence the rate of
kill are temperature, pH, presence of other materials that react with chlorine, time,
and the concentrations of the various chlorine combinations that are formed in the
water with ammonia and other substances that react with chlorine.
The fact that chlorine can be easily detected and measured makes chlorine a
favorite water sanitizer of those concerned with the public safety of water supplies.
Chlorine concentrations in the range of 0.1 to 0.4 parts per million are usually
maintained in municipal supplies.
Chlorine can be added in the form of chlorine gas, liquid sodium hypochlorite
(bleach), granular calcium hypochlorite or as organic chlorine compounds.
Chlorine is not present in natural water supplies; if it is present it is the result of
chlorination of a water supply or of chlorinated compounds being discharged as
waste from industrial operations. The presence of chlorine in concentrations above
0.5 parts per million should be considered evidence of pollution from chlorine
treated effl uents or from a process in which high concentrations of chlorine are
used.
SMART Spectro Test Procedures 2.11 CHLORINE, DPD Liquid
Test P
rocedures