Hach DR/700 - Page 205

45-33
PHENOLS, continued
10. Remove the
stoppers. Allow both
funnels to stand until
the chloroform settles
to the bottom of the
funnel.
Note: The chloroform
will be yellow to amber
if phenol is present.
11. Insert a pea-size
cotton plug into the
delivery tube of each
funnel.
12. Drain the
chloroform layers
into separate sample
cells - one for the
blank and one for the
prepared sample.
Note: Filtering the
chloroform layer
through dry cotton will
remove any suspended
water or particles. The
volume of the
chloroform extract will
be about 25 mL due to
slight solubility of
chloroform in water.
Note: Proceed promptly
through the rest of the
procedure since the
chloroform will
evaporate, causing high
readings.