Answer Posted / lalitha
What is the Karl Fischer Reaction?
ROH + SO2 + R’N �� [R’NH]SO3R + H2O + I2 + 2R’N �� 2[R’NH]I +
[R’NH]SO4R
[alcohol] [base] [alkylsulfite salt] [water] [iodine]
[hydroiodic acid salt] [alkylsulfate salt]
The alcohol reacts with sulfur dioxide (SO2) and base to
form an intermediate alkylsulfite salt, which
is then oxidized by iodine to an alkylsulfate salt. This
oxidation reaction consumes water.
The reactive alcohol is typically methanol or 2-(2-
Ethoxyethoxy)ethanol, also known as diethylene
glycol monoethyl ether (DEGEE), or another suitable alcohol.
Classic Karl Fisher reagents contained pyridine, a noxious
carcinogen, as the base. The reagents most
frequently used today are pyridine-free and contain
imidazole or primary amines instead.
Water and iodine are consumed in a 1:1 ratio in the above
reaction. Once all of the water present is
consumed, the presence of excess iodine is detected
voltametrically by the titrator’s indicator
electrode. That signals the end-point of the titration.
The amount of water present in the sample is calculated
based on the concentration of iodine in the
Karl Fisher titrating reagent (i.e., titer) and the amount
of Karl Fisher Reagent consumed in the
titration.
| Is This Answer Correct ? | 36 Yes | 1 No |
Post New Answer View All Answers
why require to do water content for drug product?
which situation gc hs and gc als require to use?
Which parameter require to do for analytical method equivalency?
What is the principle of HPLC, GC, LCMS, GCMS,LC QQQ, GC QQQ, LC Q TOF and GC Q TOF. What are the applications and Specificity?
How to set specification of assay, fisdolution and related substances?
how will you do the prep for unstable componds?
In Assy by potentio metry titration method how select MET U ,DET U, SET U,
if your product is soluble in 0.1n hcl and water then which you choose as media from these 2 media?
inhouse product is in capsule form in combination and RLD is in tablet form then can we proceed for multimedia CDP? in inhouse capsule product disso is paddle with sinker in release media is there then RLD product in tablet form then with same as paddle with sinker we can proceed n.a.?
How to calibration of the uv spectroscopy and its test?
UV and PDA detector, which have less signal to noise ratio?
in which situation require to use paddle and basket?
How can the GC or HPLC method is selected to determine the impurity profile in drug product?
what are the guidelines for analytical method validations?
Did anybody have method for acetyl cysteine effervescnce tablet
