1. Cation-active surfactants and bromophenol blue form compound with celestial-blue colouring usualy (pH=7) . Quaternary ammonium salt make solvent with greenish colour.
2. If you will add the anion-active surfactant solution to cation-active surfactant solution, that sample will be turbid.
3. Negative result first of two test demonstrate nonionic surfactant presence.
Cotland and Dumerse proposed very interesting authentication method for surface active agents. This method apply 6 reagents:
1. cerium nitrate;
2. solution of the aluminium chloride in chloroform;
3. bromine water;
4. potassium permanganate;
5. alcoholic solution of the potassium hydroxide;
6. solution mixture of the acetic anhydride and sulfuric acid.
Substances |
Structural formulas |
1
|
2
|
3
|
4
|
5
|
6
|
Sodium stearate (soap) |
RCOONa |
-
|
-
|
+
|
-
|
+
|
-
|
Sodium tallate (liquid soap) |
RCOONa |
-
|
+
(b)
|
+
|
+
|
+
|
+
|
Paraffine sulfates |
RCH2OSO3Na |
-
|
+
(a)
|
-
|
-
|
-
|
-
|
Olefine sulfates |
RCH2OSO3Na |
-
|
+
(a)
|
+
|
+
|
-
|
-
|
Alkylaryl sulfonates |
RC6H4SO3Na |
-
|
+
|
-
|
-
|
+
|
-
|
Ether of the nonsaturated fatty acids and ß-sulfaethanole |
RCOOCH2CH2SO3Na |
+
|
+
(a)
|
+
|
+
|
+
|
-
|
Alkylphenole sulfoethoxilates |
RC6H4O(CH2CH2O)nSO4Na |
+
|
+
|
+
|
-
|
+
|
-
|
Taurineamide fatty acids |
RCONHCH2 CH2SO3Na |
+
|
+
(a)
|
+
|
+
|
+
|
-
|
Oxyethylated saturated spirits |
RO(CH2CH2O)nH |
+
|
-
|
-
|
-
|
-
|
-
|
Oxyethylated nonsaturated spirits |
RO(CH2CH2O)nH |
+
|
+
|
+
|
+
|
-
|
-
|
Oxyethylated alkylphenols |
RC6H4O(CH2CH2O)nH |
+
|
+
|
+
|
-
|
-
|
-
|
Oxyethylated mercaptans |
RS(CH2CH2O)nH |
+
|
-
|
+
|
+
-
|
+
|
-
|
Oxyethylated fatty acids |
RCOO(CH2CH2O)nH |
+
|
+
|
+
|
+
|
+
|
-
|
Oxyethylated nonsaturated fatty acids |
RCOO(CH2CH2O)nH |
+
|
+
|
+
|
+
|
+
|
-
|
Oxyethylated tallate |
RCOO(CH2CH2O)nH |
+
|
+
|
+
|
+
|
+
|
+
|
Copolymers of the ethylene oxide and propylene |
[(CH3CHCH2O)x(CH2CH2O)y]nCH3 |
+
|
-
|
+
|
+
|
-
|
-
|
Sorbitan monolaurates |
RCOO(sorbitan) |
+
|
-
|
-
|
+
|
+
|
-
|
Polyoxyethylene sorbitan laurates |
RCOO(sorbitan)[(OCH2CH2O)nH]x |
+
|
+
(b)
|
+
|
+
|
+
|
-
|
Alkylamides fatty acids |
RCONHCH2CH2 OH |
+
|
-
|
+
|
+
|
+
-
|
-
|
(a) - green colour;
(b) - pink colour.
|