Hach DR/850, Procedures Manual, Page: 417 / 460

417
Method 8028
SURFACTANTS, ANIONIC
(0 to 0.300 mg/L)
For water, wastewater, and seawater
(Also called: Detergents) Crystal Violet Method
*
* Analytical Chemistry , 38, 791(1966).
1.
Enter the stored
program number for
Surfactants, anionic
(LAS).
Press:
PRGM
The display will show:
PRGM ?
2.
Press:
26 ENTER
The display will show
mg/L, LAS and the
ZERO icon .
3.
Fill a clean 500-mL
graduated cylinder to the
300-mL mark with
sample. Pour the sample
into a clean 500-mL
separatory funnel.
4.
Add 10 mL of
Sulfate Buffer Solution.
Stopper the funnel.
Shake the funnel for
five seconds.
5.
Add the contents of
one Detergents Reagent
Powder Pillow to the
funnel. Stopper the
funnel and shake to
dissolve the powder.
6.
Add 30 mL of
benzene to the funnel.
Stopper the funnel and
shake gently for
one minute.
Note: Spilled reagent will
affect test accuracy and is
hazardous to the skin and
other materials.
Note: Use benzene only in
a well-ventilated area.
7.
Place the separatory
funnel in a support stand.
8.
Press:
TIMER ENTER
A 30-minute reaction
period will begin.
Note: Excessive agitation
may cause an emulsion,
requiring a longer time for
phase separation. If this
occurs, remove most of the
water layer, then gently
agitate the funnel with a
clean inert object in the
funnel such as a Teflon-
coated magnetic
stirring bar.