PERMFILE131137

• Permit No: C1980005
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: LABORATORY PROCEDURES
• Section_Exhibit Name: TAB 06 APPENDIX 6-2
• Media Type: D
• Archive: No

~~
Hot-water Soluble_
• (ASA Agxrmany No. 9, Methods of Soil Analysis)
Page two - -
Procedure , Cont' d.
6. Add 5 ml of the Ca(OH)2 suspension to both the samples and standart3s and
evaporate to dryness in a drying ovPSS at 55°C.
7. Add 1 drop of pd~olphthalein indicator and .5 ml of 2.5 N HC1. If the
solution remains pink, add HC1 dropwise until the solution is clear.
8. Add 4 ml of the c~sclanin - oxalic acid solution and rotate the beaker to
bring the solution into contact with all of the sample.
9. Place the sample and standard beakers in a water bath so that about 1/Z"
of the beaker is in the water. Evaporate the solutions to dryness at
55°C ± 3°C. Remove the beakers from the bath 15 minutes after becoming dry.
10. Pbisten the residue with alcohol, using a wash bottle. Transfer the con-
tents to a 50 ml centrifuge with additional alcohol, using a rubber police-
man to aid in transfer. Keep total wlume below 25 ml.
11. Centrifuge the solution for 10 minutes at 2000 RPM. Decant the solution
• into a 25 ml wlumetric flask and add alcohol to bring th wlimie.
12. Measure the absorbance of the standards on the D-U spectrophotometer at
540 mu. Zero the instrument by using the blank prepared with the standards.
The absorbance reading obtained on the blank sample solution should be sub-
tracted from the sample readings.
13. Find the concentration of boron in the test solution by reference to the
calibration curve and calculate the boron onntent in the original sample.
The color is stable for 1-2 hours.
-~
14. Standards should be nm with each batch of samples.
Calculations
C~
ppm water soluble boron in sample = 4 x ug concentration for
calibration curve
The above foa!atla is derived fr+mn:
x = ug from calibration crave
x ug/ml =
20x ug/20 ml =
20x ug/5 g =
4 x ug/g =
4 x ppm boron in sample
6-56