Hach DR/850, Руководство по процедурам, Страница: 81 / 460

81
Perform the bromine analysis immediately after collection.
Accuracy Check
Standard Additions Method (using powder pillows)
a) Snap the top off a LR Chlorine PourRite
®
Ampule Standard
Solution.
b) Use a TenSette Pipet to add 0.1 mL of the standard to the
reacted sample (this is the spiked sample). Swirl to mix.
c) Re-zero the instrument using the original sample (the
blank).
d) Place the spiked sample in the cell holder and press
READ
.
Record the result.
e) Calculate the equivalent concentration of mg/L bromine
added to the sample:
f) The spiked sample result (step d) should reflect the
analyzed sample the calculated mg/L Br
2
added
(step e).
g) If this increase does not occur, see Standard Additions in
Section 1 for more information.
Standard Additions Method (using AccuVac Ampuls)
a) Snap the top off a LR Chlorine PourRite Ampule Standard
Solution.
b) Use a graduated cylinder to measure 25 mL of sample into
each of two beakers.
c) Use a TenSette Pipet to add 0.2 mL of the standard to one
of the beakers (this is the spiked sample). Swirl to mix.
d) Fill a DPD Total Chlorine AccuVac completely from each
beaker.
e) Analyze the spiked and unspiked sample as described in
the procedure.
f) Calculate the equivalent concentration of mg/L bromine
added to the sample:
mg/L Bromine added
0.1 (vol. standard added) Label value (mg/L Chlorine)
×
2.25
×
10.1 ( standard volume)
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BROMINE,
continued