GRAVIMETRIC METHOD Flashcards
Is the MEASUREMENT OF WIEGHT OF A SUBSTANCE in a sample or calculation of the weight of a substance in a sample from the weight of a chemically equivalent amount of some other substance.
GRAVIMETRIC ANALYSIS
Is the SEPARATION by extraction, precipitation or other means of the constituent to be determined either in the natural state or in the form of a definite compound the composition of which is known to the analysts, and the weighing of the resulting products.
GRAVIMETRIC ANALYSIS
Used in IGNITION of drugs and precipitates.
PLAIN CRUCIBLE
in constant weight, Two consecutive weighings do not differ by __________ of substance taken for the DETERMINATION, the second weighing following an additional hour of drying
more than 0.5mg/g
in constant weight, When two consecutive weighings AFTER HEATING & COOLING do not differ by _________
more than 0.2mg
Used to maintain a DRY ATMOSPHERE for objects that might be affected by moisture or CO2.
DESSICATOR
small sample = small product
LAW OF MASS ACTION
greater solubility = lesser precipitate
SOLUBILITY PRODUCT PRINCIPLE
other reagent that could produce the same product
COMMON ION EFFECT
Is the SEPARATION BY EXTRACTION of the constituents in the natural state, and the weighing of the final product.
PHYSICAL METHOD
Is the SEPARATION BY PRECIPITATION, ignition of a compound, electrolysis of the constituents in the form of a definite compound the composition of w/c is known to the analyst, & the weighing of the final product.
CHEMICAL METHOD
Of a crude drug is generally taken to be the RESIDUE containing AFTER INCINERATION
ASH CONTENT
the ash usually represents the ________ naturally occurring in the drug
INORGANIC SALTS
Very dull red heat
500-550
DULL RED HEAT
550-700
Is the part of the total ash which is INSOLUBLE in diluted hydrochloric acid.
ACID INSOLUBLE ASH
The ash content of chemical is determined by using NEGLIGIBLE AMOUNT (quantity not exceeding 500 µg or 0.5mg)
RESIDUE ON IGNITION
Provides a means of determining the percentage of test material which is VOLATILIZED and driven off under the condition specified.
LOSS ON IGNITION
Is the residue after the CARBONIZED MASS is treated with 1 mL of concentrated H2SO4 and further incinerated after evaporating off the H2SO4 under a hood.
SULFATED ASH
Used to ensure uniformity of water content limits in the drug. Drugs official in the USP and N.F. contain varying quantities of water either as water of crystallization (hydrates) or as water in the adsorbed form.
WATER CONTENT DETERMINATION
