Table of Contents
Advertisement
Chromium, Hexavalent
Method Performance
Chromium, Hexavalent
Page 4 of 6
5. For analysis using powder pillows, use the TenSette
0.2 mL, and 0.3 mL of standard, respectively to three 25-mL samples and mix
thoroughly. Transfer 10 mL of each solution into a 10-mL sample cell and
analyze as described above.
Note: For AccuVac ampules, fill three mixing cylinders (Cat. No. 1896-41) with 50-mL of sample
and spike with 0.2 mL, 0.4 mL, and 0.6 mL of standard. Transfer 40 mL from each of the
three mixing cylinders to three 50-mL beakers. Analyze each standard addition sample as
described in the procedure above.
6. Accept each standard additions reading by touching
should reflect approximately 100% recovery.
7. After completing the sequence, touch
the standard additions data points, accounting for matrix interferences. Touch
, then select
View: Fit
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 0.25-mg/L Cr
1. Using a 5.00 mL pipet (Cat. No. 14515-37) transfer 5.00 mL of Hexavalent
Chromium Standard Solution, 50 mg/L, into a Class A 1000-mL volumetric
flask (Cat. No. 14574-53).
2. Dilute to the mark with deionized water.
3. To adjust the calibration curve using the reading obtained with the
0.25-mg/L standard solution, touch
Touch
Standard Adjust
4. Touch
. Touch
On
Adjust
depends on the selected chemical form). If an alternate concentration is used,
touch the number in the box to enter the actual concentration, then touch
Touch
.
Adjust
Perform the hexavalent chromium procedure as described above. See Section
3.2.4 Adjusting the Standard Curve on page 40 for more information.
Precision
Standard: 0.25 mg/L Cr
Program
90
95
See Section 3.4.3 Precision on page 44 for more information, or if the standard
concentration did not fall within the specified range.
Sensitivity
Program
90
95
See Section 3.4.5 Sensitivity on page 44 for more information.
Graph
and touch
Ideal Line
OK
6+
standard solution daily, as follows:
Options
.
to accept the displayed concentration (the value
6+
95% Confidence Limits of Distribution
Portion of Curve
Entire range
Entire range
®
Pipet to add 0.1 mL,
. Each addition
Read
to view the best-fit line through
to view the relationship between
on the current program menu.
6+
0.24–0.26 mg/L Cr
6+
0.24–0.26 mg/L Cr
∆Abs
∆Concentration
0.010
0.01 mg/L Cr
0.010
0.01 mg/L Cr
ChromiumHex_AVPP_Other_DCH_Eng_Ody.fm
.
OK
6+
6+
Advertisement
Table of Contents
