
32
Metals Procedure
Note: If analyzing aliquots smaller than 0.5 mL, pH adjustment is unnecessary.
1. Pipet the appropriate analysis volume into the appropriate mixing
graduate cylinder. See Sample and Analysis Volume Tables following
the specific digestion for liquids, solids or oils to determine the
analysis volume.
Note: Some methods require pipetting into a volumetric flask or a regular
graduate cylinder.
2. Dilute to about 20 mL with deionized water.
3. Add one drop of 2,4 Dinitrophenol Indicator Solution.
4. Add one drop of 8 N Potassium Hydroxide (KOH) Standard Solution,
swirling between each addition, until the first flash of yellow appears
(pH 3). If analyzing for potassium, use 5 N sodium hydroxide instead.
Do not use a pH meter if analyzing for potassium or silver.
5. Add one drop of 1 N KOH. Stopper the cylinder and invert several
times to mix. If analyzing for potassium, use 1 N sodium hydroxide
instead.
Note: Use pH paper to insure the pH is 3. If it is higher than 4, do not readjust
with acid; start over with a fresh aliquot.
6. Continue to add 1 N KOH in this manner until the first permanent
yellow color appears (pH 3.5-4.0).
Note: High iron content will cause precipitation (brown cloud) which will co-
precipitate other metals. Repeat this procedure with a smaller aliquot volume.
7. Add deionized water to the volume indicated in the colorimetric
procedure for the parameter you are analyzing. Fill a second graduated
mixing cylinder to the same volume with deionized water.
8. Continue with the colorimetric procedure for the parameter you
are analyzing.
GENERAL DIGESDAHL DIGESTION,
continued
客服:400 688 9809
网址:www.mamots.com 电话:0431-85178766
Summary of Contents for Digesdahl 23130-20
Page 1: ...400 688 9809 www mamots com 0431 85178766...
Page 11: ...2 400 688 9809 www mamots com 0431 85178766...
Page 17: ...8 Figure 3 Fractionating Column and Exhaust Assembly 400 688 9809 www mamots com 0431 85178766...
Page 19: ...10 400 688 9809 www mamots com 0431 85178766...
Page 36: ...27 DIGESTION PROCEDURES 400 688 9809 www mamots com 0431 85178766...
Page 43: ...34 400 688 9809 www mamots com 0431 85178766...
Page 45: ...36 SAMPLE TYPE AND SIZE continued Chart 2 For Oils 400 688 9809 www mamots com 0431 85178766...
Page 60: ...51 400 688 9809 www mamots com 0431 85178766...
Page 74: ...65 400 688 9809 www mamots com 0431 85178766...
Page 89: ...80 400 688 9809 www mamots com 0431 85178766...
Page 91: ...82 400 688 9809 www mamots com 0431 85178766...
Page 93: ...84 400 688 9809 www mamots com 0431 85178766...
Page 96: ...87 HOW TO ORDER 400 688 9809 www mamots com 0431 85178766...
Page 97: ...88 REPAIR SERVICE 400 688 9809 www mamots com 0431 85178766...
Page 98: ...89 WARRANTY 400 688 9809 www mamots com 0431 85178766...
Page 99: ...400 688 9809 www mamots com 0431 85178766...