Hach DR2400 - Interfering Substances and Suggested Treatments; Sample Collection, Preservation and Storage

Boron
Boron
Page 4 of 6
Boron_PP_Low_AZO_Eng_Ody.fm
Table 2 Interfering Substances and Suggested Treatments
Sample Collection, Preservation and Storage
Collect samples in clean polyethylene bottles. Do not use borate-based
detergents or soaps to clean sample containers or labware used for this method.
After use, thoroughly rinse all plastic containers with deionized water, allow to
air dry, and keep covered.
Sample Temperature Compensation
The reaction chemistry is very dependent on the sample temperature. Hach
calibrations are performed at 23 °C (73 °F). If the sample temperature is outside
the range of 22–24 °C (72–75 °F), multiply the results, in mg/L, by the
appropriate multiplier (Table 3).
Silica 120
Sulfate 1800
Sulfite 40
Tolyltriazole 20
Zinc (
2+
)10
Table 1 Interferences (continued)
Substance Interference Level Tested
Interfering Substance Interference Levels and Treatments
Alkalinity >500 mg/L
(+ or -)
1. Adjust sample pH to between 5–7 using 1.0 N Sulfuric Acid Solution (Cat. No. 1270-32).
2. Continue with step 4 of the analytic procedure.
Color (+)
1. Zero the instrument (0.00 mg/L B) using Ultra-Pure Water (Cat. No. 25946-49).
2. Measure and record the apparent concentration, in mg/L B, due to the samples color.
3. Subtract the apparent concentration from the result in step 16 of the test procedure.
Halogens (Bromine or
Chlorine) all levels (+)
Halogen disinfectants in the sample can produce a red-color after the addition of BoroTrace™ 2
Reagent. To eliminate this interference:
1. Add 1 pillow Dechlorinating Reagent (Cat. No. 14363-69) to 25 mL each of Ultra-Pure Water
(Cat. No. 25946-49) and sample.
2. Cap and shake to dissolve.
3. Continue with step 4 of the test procedure.
Iron (Fe
3+
or Fe
2+
),
above8mg/L(+)
High levels of iron in the sample can produce a red-color after the addition of BoroTrace™ 2
Reagent. To compensate, increase the amount of EDTA (Cat. No. 22419-26) from 10 drops to 15
drops to be added to each cell (Step 5). Alternatively, dilute the sample with Ultra-Pure Water
and continue with Step 5 of the test procedure. Correct the results (Step 15) using the
appropriate dilution factor.
Nitrites, all levels (+)
1. Add 0.1 gram scoop Sulfamic Acid (Cat. No. 2344-14) to 25 mL each Ultra-Pure Water and
sample in plastic cells.
2. Cap and shake to dissolve.
3. Uncap and wait 5 minutes.
4. Add 5 N Sodium Hydroxide Reagent (Cat. No. 2450-26) solution to each to adjust pH 5–8
using pH paper.
5. Continue with step 4 of the test procedure.
Turbidity (+)
Filter the sample through a 3 µm membrane (Cat. No. 25940-25) prior to testing. Do not use a
glass fiber filter.