(A)
Preliminary
Tests
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Appearance of dye Powder
|
Amorphous
|
Direct, Acid, Basic, Sulphur, Mordant, Vat,
Naphthols, Fast bases, Salts, Rapid fast, Indigosol etc.
|
|
Crystalline
|
Some Basic dyes, Disperse dye
|
||
|
Flakes like
|
Aniline salts
|
||
|
2.
|
Colour of Powder
|
Bright, Shining
|
Basic
|
|
Bright
|
Direct, Acid, Basic, Vat, Mordant etc.
|
||
|
Dull
|
Sulphur
|
||
|
Light colour
|
Indigosols, Naphthols, Fast salts, Some Fast bases,
Rapid fast, Rapidogen etc.
|
||
|
3.
|
Weight of Powder
|
Light
|
Basic, Direct, Vat, Acid etc.
|
|
Heavy
|
Pigments
|
||
|
4.
|
Smell of Powder
|
Phenolic
|
Naphthols
|
|
Aromatic
|
Fast bases, Salts
|
||
|
Sweet Smell like chloroform
|
Indigosols
|
(B)
Solubility
Tests
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
|
1.
|
Dye Powder + Water (Heat the Solution)
Original Solution
|
A
|
Dissolves in warm but precipitated at boiling
|
Fast salts
|
|
B
|
Dissolves very freely giving a faint coloured
solution
|
Indigosols, Aniline salt
|
||
|
C
|
Dissolves very freely giving a deep coloured
solution (Transperent)
|
Direct, Basic, Reactive, Acid, Acid mordant etc.
|
||
|
D
|
Insoluble particles in suspension condition
|
Naphthol, Vat, Sulphur, Fast bases, Pigments
|
||
|
E
|
Insoluble particles in disperse condition
|
Disperse
|
||
Preliminary Tests For A
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original Solution
+ Naphthol Solution
|
Deep Coloured Solution
|
Fast salts
|
Preliminary Tests For B
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original Solution
+ NaNO2 + dil. HCl or H2SO4 &
Heat
|
Deep Coloured Precipitates
|
Indigosol
|
|
No ppts.
|
Pre –Aniline Salt
|
Preliminary Tests For C
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
|
1.
|
Original Solution
+ Tannin Reagent & Heat
|
Precipitates are obtained in few minutes
|
Basic Dye
|
|
|
No ppts.
|
Direct, Acid, Acid mordant
|
|||
|
2.
|
Original Solution + Wool + Tanned Cotton + Acetic
Acid (2 – 3 drops) & Heat
|
I
|
Both Cotton & Wool dyed in full shade. Not fast
to rubbing
|
Basic Dye
|
|
II
|
Cotton dyed deeper then wool & fast to rubbing
|
Direct Dye, Reactive dye
|
||
|
III
|
Wool is dyed & Cotton stained, it is stripped in
hot dil. NH3
|
Acid, Acid mordant
|
||
Preliminary Tests For D
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original powder + dil. HCl + NaNO2. Drop
by drop
|
A clear solution is obtained after few minutes which
give coloured ppts. With naphthol solution
|
Base
|
|
No ppts.
|
Naphthol, Vat, Sulphur etc.
|
||
|
2.
|
Powder + NaOH solution + Water & Heat
|
Dissolve freely giving clear solution
|
Naphthol, Rapidogen
|
|
Insoluble
|
Sulphur, Vat
|
||
|
3.
|
Original Solution + dil. Acetic acid or Formic acid
& Heat
|
Coloures ppts.
|
Rapidogen
|
|
ppts. as Original substance
|
Naphthol
|
||
|
4.
|
Powder + Na2S & Heat
|
Dissolve freely with a change in colour
|
Sulphur
|
|
Do not dissolves
|
Vat
|
||
|
5.
|
Powder + NaOH + Na2S2O4
& Heat
|
Dissolve with a change in colour
|
Vat
|
(C)
Confirmative
Tests
Confirmative
Tests for Fast Salt
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original Solution + Naphtholated yarn
|
Deep colour
Yarn dyed in full shade
|
Fast Salt
|
|
2.
|
Fastness test
|
Not fast to rubbing
|
Fast salt
|
Confirmative
Tests for Indigosols
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original Solution + NaNO2 + Cotton, Warm
squeeze & put in hot dil H2SO4 Solution
|
Cotton gets dyed, in full shade
|
Indigosol
|
|
2.
|
Dyed yarn + NaOH + Hydro, & Heat
|
Colour is reduced & restored in air or
persulphite
|
Indigosol
|
|
3.
|
Fastness test
|
Fast to all
|
Indigosol
|
Confirmative Tests
for Aniline Salt
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original Solution + dil H2SO4 +
Cotton + K2Cr2O7 (drop) & Heat
|
Cotton is dyed, from brown to black colour
|
Aniline salt
|
|
2.
|
Bleaching test
|
Turns brown or diminished
|
Aniline salt
|
|
3.
|
Fastness test to rubbing
|
Not fast to rubbing
|
Aniline salt
|
Confirmative Tests
for Basic Dye
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Dyed wool + white Cotton + white Wool + Soap
solution & heat
|
White Wool is dyed deeper than white Cotton
|
Basic dye
|
|
2.
|
Dyed wool + 10 % Sodium hydrosulphite solution
|
Dye is not stripped and no effect on original shade
|
Basic dye
|
Confirmative Tests
for Direct Dye
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original solution + Cotton +
2 – 3 drops Soda ash + NaCl Boil
|
Cotton is dyed in deep shade
|
Direct dye
|
|
2.
|
Dyed cotton + NaOCl solution
|
Colour is discharge within
5 – 7 minutes
|
Direct dye
|
|
3.
|
Dyed cotton + white Cotton + Soap solution, Boil
|
White cotton stained
|
Direct dye
|
Confirmative
Tests for Reactive Dye
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original Solution + Cotton & after dyeing add
Cotton & H2SO4
|
Dye stained untreated cotton and partially stripped
from dyed cotton
|
Reactive dye
|
|
2.
|
Above dyed cotton + Pyridine or Chloroform , Warm
|
No effect
|
Reactive dye
|
Confirmative
Tests for Acid Dye
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original Solution + Wool + CH3COOH + Cotton
& Heat
|
Wool dyed deeper than Cotton or Cotton is not dyed
|
Acid dye
|
|
2.
|
Dyed wool + Strong hydrosulphite solution
|
Dye stripped from the dyed fibre
|
Acid dye
|
|
3.
|
Dyed wool + K2Cr2O7
+ water & Heat for 5 minutes (Treated wool) + Soap solution, Boil
& untreated dyed wool + soap solution & boil
separately
|
Colour is stripped from both dyed samples
|
Acid dye
|
Confirmative Tests
for Acid Mordant
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original Solution + Wool + Cotton & Heat
|
Wool dyed deeper than Cotton or Cotton is not dyed
|
Acid mordant
|
|
2.
|
Dyed wool + drop of
K2Cr2O7 + Water & Heat
|
Colour become deeper or changed on tone
|
Acid mordant
|
|
3.
|
Dyed wool (untreated with K2Cr2O7)
+ Soap solution & Heat
|
Colour stripped
|
Acid mordant
|
Confirmative
Tests for Fast Base
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original Solution* + Naphtholated yarn
|
Yarn is dyed in deep full colour
|
Fast Base
|
|
2.
|
Fastness to rubbing
|
Not fast to rubbing
|
Fast Base
|
|
3.
|
Dyed cotton + NaOCl solution
|
No change in colour of the dyed cotton
|
Fast Base
|
|
4.
|
Dyed cotton + Rongolite – C + CH3COOH ,
Boil
|
Original colour of the dyed cotton is changed
|
Fast Base
|
·
Original
solution made by HCl + NaNO2 +Sodium acetate
Confirmative
Tests for Rapidogen
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original solution + Yarn + Hot Acetic acid
|
Yarns get dyed
|
Rapidogen
|
Confirmative Tests
for Naphthol
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Original solution + Fast salt
|
Deep coloured ppts.
|
Naphthol
|
|
2.
|
Original Solution + Yarn & put it in fast salt
solution
|
Yarn gets dyed in full shade
|
Naphthol
|
Confirmative
Tests for Sulphur Dye
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Powder + SnCl2 + Conc. HCl & Heat
|
Lead acetate paper turns brown to black with silvery
effect
|
Sulphur dye
|
|
2.
|
Fastness to bleaching
|
Loose to bleach
|
Sulphur dye
|
|
3.
|
Powder + Na2S + cotton & Heat
|
Cotton dyed with full deep colour
|
Sulphur dye
|
Confirmative
Tests for Vat Dye
|
Sr.
No.
|
TESTS
|
OBSERVATION
|
INFERENCE
|
|
1.
|
Dyed cotton + Soap solution Boil for 2 minutes
|
Colour is not remove
|
Vat dye
|
|
2.
|
Dyed cotton + NaOCl
|
Fast to bleach
|
Vat dye
|
|
3.
|
Dyed fibre +
Formic acid (85 %), Boil
|
Colour is not remove
|
Vat dye
|
|
4.
|
Dyed fibre + Na2S2O4
solution
|
No change in colour
|
Vat dye
|
