Propionic acid

Prepared at the 49th JECFA (1997)
superseding specifications prepared at the 44th JECFA (1995),
published in FNP 52 Addendum 3 (1995)

TENTATIVE

Information required on method of analysis and levels for readily oxidizable substances

SYNONYMS

Propanoic acid, ethylformic acid, methylacetic acid, INS No. 280

DEFINITION

Chemical name

Propionic acid

C.A.S. number

79-09-4

Chemical formula

C₃H₆O₂

Structural formula

CH₃CH₂COOH

Formula weight

74.08

Assay

Not less than 99.5% on dried basis

DESCRIPTION

An oily liquid with a slightly pungent odour

FUNCTIONAL USES

Preservative, antimould, antirope agent, flavouring agent (see "flavouring agents" monograph)

CHARACTERISTICS

IDENTIFICATION

Solubility

Miscible with water and ethanol

Specific gravity

: 0.993 - 0.997

PURITY

Distillation range

138.5 - 142.5°

Non-volatile residue

Not more than 0.01% when dried at 140° to constant weight

Readily oxidizable substances

Information required

Heavy metals

Not more than 10 mg/kg
Test 2 g of the sample as directed in the Limit Test (Method II).

Aldehydes

Not more than 0.2% (as propionaldehyde)
See description under TESTS.

TESTS

PURITY TESTS

Aldehydes

Transfer 10.0 ml of the sample into a 250-ml glass-stoppered conical flask containing 50 ml of water and 10.0 ml of a 1 in 8 solution of sodium bisulfite. Stopper the flask, and shake vigorously. Allow the mixture to stand for 30 min, then titrate with 0.1N iodine to the same brownish yellow end-point obtained with a blank treated with the same quantities of the same reagents. The difference between the volume of 0.1N iodine required for the blank and that required for the sample is not more than 7 ml.

METHOD OF ASSAY

Mix 3 g of the sample, weighed to the nearest 0.1 mg, with 50 ml of water in a 250-ml flask. Add phenolphthalein TS, and titrate with IN sodium hydroxide to the first appearance of a faint pink end-point which persists for at least 30 sec. Each ml of IN sodium hydroxide is equivalent to 74.08 mg of C₃H₆O₂.

TENTATIVE	Information required on method of analysis and levels for readily oxidizable substances
SYNONYMS	Propanoic acid, ethylformic acid, methylacetic acid, INS No. 280
DEFINITION
Chemical name	Propionic acid
C.A.S. number	79-09-4
Chemical formula	C₃H₆O₂
Structural formula	CH₃CH₂COOH
Formula weight	74.08
Assay	Not less than 99.5% on dried basis
DESCRIPTION	An oily liquid with a slightly pungent odour
FUNCTIONAL USES	Preservative, antimould, antirope agent, flavouring agent (see "flavouring agents" monograph)
CHARACTERISTICS
IDENTIFICATION
Solubility	Miscible with water and ethanol
Specific gravity	: 0.993 - 0.997
PURITY
Distillation range	138.5 - 142.5°
Non-volatile residue	Not more than 0.01% when dried at 140° to constant weight
Readily oxidizable substances
	Information required
Heavy metals	Not more than 10 mg/kg Test 2 g of the sample as directed in the Limit Test (Method II).
Aldehydes	Not more than 0.2% (as propionaldehyde) See description under TESTS.
TESTS
PURITY TESTS
Aldehydes	Transfer 10.0 ml of the sample into a 250-ml glass-stoppered conical flask containing 50 ml of water and 10.0 ml of a 1 in 8 solution of sodium bisulfite. Stopper the flask, and shake vigorously. Allow the mixture to stand for 30 min, then titrate with 0.1N iodine to the same brownish yellow end-point obtained with a blank treated with the same quantities of the same reagents. The difference between the volume of 0.1N iodine required for the blank and that required for the sample is not more than 7 ml.
METHOD OF ASSAY	Mix 3 g of the sample, weighed to the nearest 0.1 mg, with 50 ml of water in a 250-ml flask. Add phenolphthalein TS, and titrate with IN sodium hydroxide to the first appearance of a faint pink end-point which persists for at least 30 sec. Each ml of IN sodium hydroxide is equivalent to 74.08 mg of C₃H₆O₂.