Hach DR/700 Procedures Manual page 639

SULFIDE
For water, wastewater and seawater
Methylene Blue Method*; USEPA accepted for reporting**
1.
Install module
61.01
in a DR/700.
Note: Samples must be
analyzed immediately
and cannot be preserved
for later analysis. Avoid
excessive agitation.
4.
Fill a 25-mL
sample cell to the
25 mL line with
sample (the prepared
sample).
Note: For turbid
samples, see
Interferences following
these steps for
pretreatment
instructions.
*Adapted from Standard Methods for the Examination of Water and Wastewater.
**Procedure is equivalent to USEPA method 376.2 and Standard Method 4500-S
wastewater.
(0 to 0.600 mg/L S
2.
Press:
I/O
The display will show
610 nm
and module number
61.01
5.
Fill another 25-mL
cell to the 25 mL line
with demineralized
water (the blank).
61-83
Method 8131
2-
)
3.
After 2 seconds,
the display will show
a program number,
concentration units,
decimal position and
the zero prompt. If
necessary, press the
UP ARROW
the lower display
shows program
number
61.12.1
6.
Add 1.0 mL of
Sulfide 1 Reagent to
each cell. Swirl to
mix.
key until
2-
D for