Commission Directive 2008/84/EC (repealed)Show full title

E 468 CROSS-LINKED SODIUM CARBOXYMETHYLCELLULOSE

Synonyms	Cross-linked carboxymethyl cellulose
	Cross-linked CMC
	Cross-linked sodium CMC
	Cross-linked cellulose gum
Definition	Cross-linked sodium carboxymethyl cellulose is the sodium salt of thermally cross-linked partly O-carboxymethylated cellulose
Chemical name	Sodium salt of the cross-linked carboxymethyl ether cellulose
Chemical formula	The polymers containing substituted anhydroglucose units with the general formula:
	C6H7O2(OR1)(OR2)(OR3)
	where R1, R2 and R3 may be any of the following: H CH2COONa CH2COOH
Description	Slightly hygroscopic, white to off white, odourless powder
Identification
A.	Shake 1 g with 100 ml of a solution containing 4 mg/kg methylene blue and allow to settle. The substance to be examined absorbs the methylene blue and settles as a blue, fibrous mass
B.	Shake 1 g with 50 ml of water. Transfer 1 ml of the mixture to a test tube, add 1 ml water and 0,05 ml of freshly prepared 40 g/l solution of alpha-naphthol in methanol. Incline the test tube and add carefully 2 ml of sulphuric acid down the side so that it forms a lower layer. A reddish-violet colour develops at the interface
C.	It gives the reaction of sodium
Purity
Loss on drying	Not more than 6 % (105 oC, 3h)
Water solubles	Not more than 10 %
Degree of substitution	Not less than 0,2 and not more than 1,5 carboxymethyl groups per anhydroglucose unit
pH of 1 %	Not less than 5,0 and not more than 7,0
Sodium content	Not more than 12,4 % on anhydrous basis
Arsenic	Not more than 3 mg/kg
Lead	Not more than 5 mg/kg
Cadmium	Not more than 1 mg/kg
Mercury	Not more than 1 mg/kg