Special Methods Flashcards
Quantitative analysis of crude drugs and derived products
Establish purity
Determine amount of therapeutically active constituents present
Purpose: Standardization
The residue remaining after incineration
Ash content
What does Ash content represent
Inorganic salts
Naturally occurring and adhering to ash content
Inorganic salts
Ash content is a basis for
Jusding the identity and cleanliness of a drug
Gives information relative to its adulteration with inorganic matter
The ash or residue yielded by an organic chemical compound is a measure of the amount of _____ present as ________
The ash or residue yielded by an organic chemical compound is a measure of the amount of inorganic matter present as IMPURITY
Very dull red heat
500 - 550 °C
Dull red heat
550 - 700 °C
Bright red heat
800 - 1000 °C
Yellow-Red heat
1000 - 1200 °C
White Heat
1200 - 1600 °C
Most important gravimetric factor
Temperature
Sample used in Total Ash
2 - 4g of the air-dried material
Temperature of Total Ash
675 +/- 25°C (Should not excedd dull redness)
Total Ash contains
Carbonates, Phosphates, Sulfates, Chlorides
Oxides of Na, K, Ca, Mg, Al, Fe, and other mettallic constituents
TF: Total Ash do not represent all the inorganic constituents
True
Formula for Total Ash Determination
% Total Ash = (Wt e.c + Wt c+r) - Wt e.c / Wc + s - W e.c
Part of the total ash which is insoluble in diluted or 3N HCl Acid
Acid-Insoluble Ash
Boiling the ash obtained in Total Ash with 25 ml of HCl for 5 minutes
Acid-Insoluble Ash
Substance used for dissolving the Calcium carbonate, alkali fluoride leaving an acid insoluble residue
HCl
Acid-insoluble residue
Silica derived from soil
Formula for Acid-Insoluble Ash
% Acid-insoluble Ash = Wt AIA / Wt. Total Ash x 100
Part of Total Ash soluble in water after ignition at 450°C
Water Soluble Ash
Water Soluble Ash is useful for detecting what
Samples which have been extracted with water
