Assays that employ IODIMETRY & IODOMETRY

Ascorbic Acid (USP/NF)

May also be analyzed using Dichlorophenol-Indophenol (DCIP) VS

(an oxidizing agent)

Dichlorophenol-Indophenol (DCIP) VS

Ascorbic Acid (USP/NF) May also be analyzed using ___ (an oxidizing agent)

Dichlorophenol-Indophenol (DCIP) VS

an oxidizing agent

Dichlorophenol-Indophenol (DCIP) VS

also used in determining ascorbic acid content

in tablets and injection, and in hexavitamin and decavitamin capsules and

tablets.

Ascorbic Acid (C6H8O6)

No indicator is necessary

indicator

No _ is necessary since DCIP is blue in alkali and red in acid,

while colorless in its reduced form.

DCIP

No indicator is necessary since _ is blue in alkali and red in acid,

while colorless in its reduced form.

blue

No indicator is necessary since DCIP is _ in alkali

red

No indicator is necessary since DCIP is _ in acid

colorless

No indicator is necessary since DCIP is _ in its reduced form.

A solution of Ascorbic Acid (with metaphosphoric acid and acetic acid) is

titrated until a rose-pink color persists.

Ascorbic Acid

A solution of _ (with metaphosphoric acid and acetic acid) is

titrated until a rose-pink color persists.

metaphosphoric acid and acetic acid

A solution of Ascorbic Acid (with _ 2) is

titrated until a rose-pink color persists.

Direct Titration

Residual Titration

Iodimetry Types of titration 2

• Antimony potassium tartrate

• Dimercaprol (with blank determination)

• Sodium ascorbate

• Sodium thiosulfate

• Sulfur dioxide

Direct Titration 5 Iodimetry

• Isoniazid

• Mild mercurous chloride

• Methionine

Residual Titration 3 Iodimetry

Direct Titration

Residual Titration

Iodometry Types of titration 2

• Arsanilic acid

• Chromic chloride

• Cupric sulfate (with blank determination)

• Selenium sulfide (with blank determination)

• Sodium hypochlorite solution

• Thyroid

Direct Titration 6 Iodometry

Sodium borohydride

Residual Titration 1 Iodometry

IODIMETRY

Direct titration using standard iodine solution

Standard iodine solution.

IODIMETRY Volumetric Solution

Reducing agent (RA)

IODIMETRY Analyte (OA or RA?)

Starch solution

IODIMETRY Indicator

Added at the start

IODIMETRY Addition of indicator (start or near endpoint?)

Blue to colorless

IODIMETRY Endpoint transition

Ascorbic acid, sulfur dioxide, etc.

IODIMETRY Sample drugs (direct)

Not applicable

IODIMETRY Sample drugs (residual)

IODOMETRY

Indirect titration where iodine is liberated and then titrated.

Standard sodium thiosulfate solution

IODOMETRY Volumetric Solution

Oxidizing agent (OA)

IODOMETRY Analyte (OA or RA?)

Starch solution

IODOMETRY Indicator

Added near the endpoint

IODOMETRY Addition of indicator (start or near endpoint?)

Blue to colorless

IODOMETRY Endpoint transition

Not applicable

IODOMETRY Sample drugs (direct)

Copper(II) salts, chlorine, hydrogen peroxide, etc

IODOMETRY Sample drugs (residual)