Millipore Spectroquant Multy Operating Manual page 223

Standard solution of total hardness
Preparation of a standard solution:
Dissolve 2.946 g of calcium nitrate tetrahydrate with distilled
water in a calibrated or conformity-checked 500-ml volu metric
flask and make up to the mark with distilled water.
The standard solution prepared according to this procedure has
a concentration of 1000 mg/l calcium (corresponds to 175 °e).
Further investigational concentrations may be prepared from
this standard solution by diluting accordingly with distilled
water.
Stability:
The standard solution of 1000 mg/l remains stable for one
week. The diluted standard solutions (investigational concen-
trations) remain stable for one day.
Standard solution of volatile organic acids
Preparation of a standard solution:
Dissolve 2.05 g of sodium acetate anhydrous with distilled
water in a calibrated or conformity-checked 1000-ml volu metric
flask and make up to the mark with distilled water.
The standard solution prepared according to this procedure has
a concentration of 1500 mg/l acetic acid.
Stability:
When stored in a cool place (refrigerator), the standard so-
lution remains stable for one week.
Reagents required:
1.02121.0500 Calcium nitrate tetra-
hydrate for analysis
EMSURE®
1.16754.9010 Water for analysis
EMSURE®
Reagents required:
1.06268.0250 Sodium acetate
anhydrous for
analysis EMSURE®
1.16754.9010 Water for analysis
EMSURE®
Chapter 5.2 | Page 23 of 23