Chemical test for Tragacanth

Chemical test for Tragacanth

Organoleptic test:

Appearance: Crystalline                                                          tragacanth

Colour: White or faint yellow                                                 tragacanth

Odour: None                                                                           tragacanth

Taste: Mucilaginous                                                                tragacanth

Solubility: Insoluble in alcohol, partially soluble in water      tragacanth

Chemical test:

SI.No.	Test	Observation		Inference
1.	To 4ml of 0.5%w/v solution add  0.5ml of HCl and heat for 30minutes on water bath Divide the hydrolyzed product in 2 parts a)      1st part=Add 1.5ml of NaOH solution to neutralize and add Fehling’s solution A and B in equal quantities(mixed before) and warm over water bath. b)      2nd part= Add barium chloride solution		Red ppt of cuprous oxide No ppt	Reducing sugars are present Distinction from agar
2.	Tragacanth solution(boil)+ 10% aq. Ferric chloride solution		Deep yellow ppt	Tragacanth may be present
3.	Tragacanth + conc. Ammonium hydroxide + precipitated copper oxide		Stingy ppt	Tragacanth may be present
4.	To 0.5% w/v solution add 20%w/v solution of lead acetate		Heavy white flocculent ppt	Distinction from acacia
5.	Mount a small quantity of powder in ruthenium red and examine microscopically		Particles do not acquire pink colour	Distinction from Indian tragacanth and agar
6.	To 0.1gm of powder add N/50 iodine		The mixture acquired greenish colour	Distinction from acacia and agar
7.	If powder is warmed with 5% alcoholic KOH solution		Canary yellow colour	Tragacanth confirmed