Procedure; Stage 1
1.
Weigh 0.5g of sample into a kjedal flask and add 20ml
of sodium tetraoxosulphate (v) or potassium tetraoxosulphate (v). 1g of Copper (II) sulphate.
2.
Heat with heating mantle (Bunsen burner) till solution
digests completely and change to bluish green color changes to white.
Stage 2; Distillation
1.
Add 200ml of distilled water to dissolve the digested
solid sample and allow cooling in a refrigerator.
2.
Add 60ml of 40% NaOH to the digested sample and pieces
of Zn metal to a beaker and connect the mixture to a distillation column and
heating mantle.
3.
In the set up, add 100ml of 4% boric acid to a conical
flask and 2 drops of screened methyl red indicator and place beneath condenser
to collect the distillate from the sample when it reaches 200ml and stop.
Stage; 3 Titration
1.
Titrate the distillate which is 200ml with 0.1N of H2SO4.
Stop titration when the color of the
distillate turns to the initial color of the mixture of boric acid and screen
methyl red indicator. (Pink color shows end point).
2.
Calculations; using the following equation to determine
% protein content.
%protein content
= (100×Tv×0.0014×6.25) ÷
wt of sample used.
Tv
= titre value.
Fat Content Determination
Procedure; use
cold extraction method.
1.
Weigh 10g of sample, measure 50ml of n-hexane and cover
24h (using foil or tape).
2.
Weigh a clean and dried empty beaker. After 24hrs
decant into weighed beaker and heat to dryness, cool and weigh.
3.
Calculations; using the following equation to determine
% fat content.
%
fat content = weight after heating−weight
of empty beaker
Carbohydrate Content Determination
Procedure;
The % of
carbohydrate content is estimated using method of difference stated bellow;
%carbohydrate =
100 %−( % moisture +
%protein + % crude fiber + % ash + % fats).
Water Analysis
Water analysis is chemical and physical process of analyzing water
samples in other to determine the substances (organic and in organic substances)
present in the water sample. This serves as criteria for establishing standard
for water in different areas of consumption. It also serves as a means of
comparing the parameter of different water samples and the already existing
standard by standard organizations (SON, NAFDAC, NIS and WHO). Water analysis
comprises of three major parameters which includes:
·
Physical parameters analysis
·
Chemical parameter analysis (CE)
·
Biochemical parameter analysis (BOC)
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