B. Samples should be previously unprepared or unprocessed: 
that is, they should not have undergone any other type of 
analysis that involves acid digestion as sample preparation 
(such as in pollen analysis). 
C. Samples should be reduced to particulates either with a 
porcelian mortar and pestle, or a metallic grinder. 
D. At all times samples should be protected against atmos- 
pheric dust and any other contaminant. 
. PREPARATION OF REAGENTS 
A. All reagents and distilled water should be stored in non- 
borosilicate containers (see 1.,A) and protected from contam- 
ination (see 1.,D). 
B. Distilled water should be known to be low in silica. 
C. HYDROCHLORIC ACID (1:1): prepare HCL (1:1) by 
adding equal volumes of HCL and distilled water. 
D. HYDROCHLORIC ACID (1:50): prepare HCL (1:50) by 
diluting one volume of HCL with fifty volume of distilled 
water. 
E. SULFURIC ACID (1:1): prepare H,SO, (1:1) by adding 
equal volumes of H»SO, and distilled water. 
F. HYDROFLUORIC ACID (1:1): prepare HF (1:1) by 
adding equal volumes of HF and distilled water. 
G. PERCHLORIC ACID (7:3): prepare HCLO, (7:3) by 
diluting seven volumes of HCLO, with three volumes of dis- 
tilled water. (Perchloric acid is explosive in the presence of 
Organic matter; exercise due caution). 
. PREPARATION OF BLANKS 
A. Prepare a reagent blank of five milliliters of distilled 
water. 
B. Run test procedure as in 4, including additions of acids, 
evaporations and ignitions, on this reagent blank. 
4. Test! 
A. DEHYDRATION 
'This test eliminates interferences due to tannin, color and turbidity. 
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