Hach DR/700 Procedures Manual page 668

TANNIN AND LIGNIN,
4.
Fill a 25-mL cell
to the 25-mL line
with demineralized
water (the blank).
continued
5.
Fill another 25-mL
cell to the 25-mL line
with sample (the
prepared sample).
Note: Filter samples that
are highly turbid. Report
results as mg/L soluble
tannic acid.
Note: For proof of
accuracy, use a 2.0 mg/L
tannic acid standard
solution (preparation
given in Accuracy
Check) in place of the
sample.
69-8
6.
Pipet 0.5 mL of
TanniVer 3 Tannin-
Lignin Reagent into
each cell. Cap and
invert several times to
mix.