Page 35 - Feed Lab

Suguna Management System Ver 1.0 / SOP / FQL / P1 - 05 Page 1 of 2

5. Laboratory Water

SCOPE WATER FOR LABORATORY USE
All water used by the laboratory to prepare reagents, wash Distilled water in any laboratory is the life of the all-chemical
glassware, or that comes into contact with samples. analysis. Success of many of the analysis will depend upon
purity of the distilled water.
RESPONSIBILITY
The British standard (ISO 3696 - 1987) recognize three
FChemist performs water analysis according to SOP.
different grads of water.
FAsst Manager specifies procedures used are
appropriate. GRADE: 1
Water is suitable for the most important requirements
EQUIPMENT
including high performance liquid chromatography and the
FAuto pipette 1 ml
determination of substances present in trace amount. Such
FAuto pipette 5 ml water is obtained by subjecting grade 2 water reverse
FDispenser osmosis or de ionization, followed by filtration through a
membrane filter of pore size 0.2 µm to particular matter.
FHotplate
Alternatively, grade 2 water may be re distilled in an
apparatus constructed from fused silica..
TESTING THE WATER
FChloride : To 100 ml of test water add 5 drops of nitric GRADE: 2
acid and 1 ml of silver nitrate. No cloudiness should be
produced. Water is suitable for more sensitive analytical
procedures, such as atomic absorption
spectroscopy and the determination of substances in
Note: Use chlorinated tap water as a control.
FOxidizable substances: To 100 ml of test water add 10 trace quantities. Water of this quality can be prepared
ml of 2 N sulphuric acid, and heat to boiling. Add 0.1 ml by re distillation of Grade 3 distilled water, or by the
of 0.1 N potassium permanganate, and boil for 10 distillation of de-ionized water or of the product of
minutes. The pink colour should not completely reverse osmosis procedures.
disappear.
GRADE: 3
FAmmonia: Add 2 ml of alkaline mercuric potassium
iodide test solution to 100 ml of test water: Any yellow Water is suitable for ordinary analytical purposes and
colour produced immediately should not be darker than may be prepared by single distillation of tap water.
the control containing 30g of added NH in 100 ml of
3
high purity water.

Prepared by : Approved by :
25 Director - Technical