Hach DR2400 - Page 121

Boron
Boron
Boron_PP_Low_AZO_Eng_Ody.fm Page 5 of 6
Table 3 Sample Temperature Multipliers
Accuracy Check
Standard Additions Method (Sample Spike)
1. After reading test results, leave the sample cell (unspiked sample) in the
instrument. Verify the chemical form.
2. Touch
Options. Touch Standard Additions. A summary of the standard
additions procedure will appear.
3. Touch
OK to accept the default values for standard concentration, sample
volume, and spike volumes. Touch
Edit to change these values. After values
are accepted, the unspiked sample reading will appear in the top row. See
Standard Additions in the instrument manual for more information.
4. Prepare a 50.0-mg/L boron standard by pipetting 5.0 mL of a 1000-mg/L
Boron Standard Solution into a 100-mL plastic volumetric flask. Dilute with
deionized water, stopper and invert to mix.
5. Prepare three sample spikes. Fill three mixing cylinders (Cat. No. 1896-40)
with 25 mL of sample. Use the TenSette
®
Pipet to add 0.1 mL, 0.2 mL, and
0.3 mL of standard, respectively, to each sample and mix thoroughly.
6. Analyze each sample spike as described in the procedure above, starting with
the 0.1 mL sample spike. Accept each standard additions reading by touching
Read. Each addition should reflect approximately 100% recovery.
7. After completing the sequence, touch
Graph to view the best-fit line through
the standard additions data points, accounting for matrix interferences. Touch
View: Fit, then select Ideal Line and touch OK to view the relationship between
the sample spikes and the “Ideal Line” of 100% recovery.
See Section 3.2.2 Standard Additions on page 32 for more information.
Standard Solution Method
Prepare a 1.0-mg/L B standard as follows:
1. Using plastic pipet, transfer 4.0 mL of Boron Standard Solution, 250-mg/L as
B, into a 1000-mL plastic volumetric flask. Dilute to volume with deionized
water, stopper and invert to mix.
2. To adjust the calibration curve using the reading obtained with the 1.0-mg/L
standard solution, touch
Options on the current program menu. Touch
Standard Adjust.
Sample Temp.
Multiplier
Sample Temp.
Multiplier
°C °F °C °F
5 41 0.70 20 68 0.94
7 450.7325 771.04
10 10 0.78 26 79 1.06
12 54 0.81 27 81 1.08
14 57 0.84 28 82 1.10
16 61 0.87 29 84 1.12
18 64 0.91 30 86 1.15