A.S.T.M. REAGENT GRADE WATER STANDARDS
(A.S.T.M. SPECIFICATION D1193-91)
|
PROPERTY
|
TYPE I
|
TYPE II
|
TYPE III
|
TYPE IV
|
|
CONDUCTANCE
|
.056 uS/cm
|
1.0 uS/cm
|
.25 uS/cm
|
5.0 uS/cm
|
|
RESISTIVITY
|
18.0 MOhm/cm
|
1.0 MOhm/cm
|
4.0 MOhm/cm
|
.20 MOhm/cm
|
|
pH
|
N/A
|
N/A
|
N/A
|
5.0 — 8.0
|
|
TOTAL SILICA
|
3.0 ug/l
|
3.0 ug/l
|
500 ug/l
|
NO LIMIT
|
|
SODIUM
|
1 ug/l
|
5 ug/l
|
10 ug/l
|
50 ug/l
|
|
CHLORIDES
|
1 ug/l
|
5 ug/l
|
10 ug/l
|
50 ug/l
|
|
T.O.C.
|
100 ug/l
|
50 ug/l
|
200 ug/l
|
NO LIMIT
|
MICROBIOLOGICAL CONTAMINATION:
When bacteria levels need to be controlled, reagent grade types should
be further classified:
|
CONTAMINANT
|
TYPE A
|
TYPE B
|
TYPE C
|
|
MAX VIABLE BACTERIA COUNT
|
10 CFU / 1000 ml
|
10 CFU / 100 ml
|
100 CFU / 10 ml
|
|
ENDOTOXIN UNITS
|
<0.03 EU/ml
|
.25 EU/ml
|
N/A
|
METHODS OF WATER PREPARATION:
|
REAGENT GRADE WATER TYPE
|
ACCEPTABLE PREPARATION TECHNOLOGIES
|
|
TYPE I
|
Distillation or other equal process, followed by polishing with
a mixed bed of ion exchange materials and a 0.2 um membrane filter.
Feed water to the final polishing step must have a maximum conductivity
of 20 uS/cm at 25 degrees C.
|
|
TYPE II
|
Distillation using a still designed to produce a distillate having
conductivity of less than 1.0 uS/cm at 25 degrees C. Ion exchange,
distillation or reverse osmosis and organic adsorption may be
required prior to distillation if the purity can not be attained
by single distillation.
|
|
TYPE III
|
Distillation, ion exchange, reverse osmosis and organic adsorption,
or a combination thereof, followed by polishing with a .45 um
membrane filter.
|
|
TYPE IV
|
Distillation, ion exchange, reverse osmosis, electrodialysis,
or a combination thereof.
|
UPDATED: 3/99
