Hanna Instruments HI 38035 - Manual (Page 2)

HEALTH AND SAFETY HEALTH AND SAFETY HEALTH AND SAFETY HEALTH AND SAFETY HEALTH AND SAFETY
The chemicals contained in this test kit may be hazardous if
improperly handled. Read the relevant Health and Safety
Data Sheets before performing the test.
REFERENCES REFERENCES REFERENCES REFERENCES REFERENCES
Standard Methods for the Examination of Water and Waste-
water, 16
th Edition, 1985, p. 210-214.
1987 Annual Book of ASTM Standard, vol. 11.01 Water
(1), p. 212-215.
Adaptation of determination of calcium with zincon indica-
tor.
• Take the syringe and push
the plunger completely down
into the syringe. Insert tip into
the HI 38035D-0 Calcium Re-
agent and pull the plunger
out until the lower edge of the
seal is on the 0.0 mL mark of
the syringe.
• Slowly add the titration solution drop by drop, swirl
after each drop and wait a few seconds.
• Continue adding HI 38035D-0 reagent until the solu-
tion in the vessel turns orange. Wait for 30 seconds and
if the solution in the vessel becomes violet, add another
drop of HI 38035D-0 reagent to turn it orange.
• Read off the milliliters of titration solution used from the
syringe and multiply by 20 to obtain the calcium
concentration as gpg CaCO
3
. Multiply the milliliters by 8
to obtain the calcium concentration as gpg Ca in your
sample.
Calculate the calcium concentration as:
mL of titrant x 20 = gpg CaCO
3
mL of titrant x 8 = gpg Ca
• To obtain the magnesium concentration subtract cal-
cium concentration from the total hardness:
gpg Mg (as CaCO
3
)=
= gpg Total Hardness (as CaCO
3
)- gpg Ca (as CaCO
3
)
Interferences: interference may be caused by an excessive
amount of heavy metals (Zn, Co, Cu, Ni, Hg).