Calculate in accordance with item 7.1.1 the area of the chloroform and acetonitrile peaks of the chromatograms obtained by the procedure described in section 6.3.4.

This method is used for the determination of chloroform in toothpaste by gas chromatography. This method is suitable for the determination of chloroform at levels of 5 % or less.

The sample is suspended in a dilute solution of metaphosphoric acid and extracted with chloroform.

Filter into a 500 ml Erlenmeyer and wash the residue with 100 ml of chloroform (3.1).

After elution of the last chloroform wash, add 5 ml of the Carr-Price reagent to the top of the column.

The alkaloids are dissolved in a mixture of diethyl ether and chloroform and extracted with hydrochloric acid.

After centrifuging, a portion of the liquid phase is subjected to gas chromatography and the chloroform content calculated.

Measure the absorbency of the chloroform solution with a photometer at 650 nm in 1 to 5 cm cells against chloroform.

A dd to each flask 30 ml chloroform (3.3) and 25 ml metaphosphoric acid solution (3.2) at 4 şC.

Add to each flask 30 ml chloroform (3.3) and 25 ml metaphosphoric acid solution (3.2) at 4 ĹźC.

The test portion is concentrated under reduced pressure, dissolved in water and purified by chloroform extraction.

The absorbency of the blank chloroform phase, measured against chloroform must not exceed 0,015 per 1 cm of layer thickness at 650 nm.

Extract the alkaline and acid solutions three times, using 10 ml of chloroform for the second and third extractions.

Add to the sample 10 ml of buffer solution (2.2.1), 5 ml of neutral methylene blue solution (2.2.2) and 15 ml of chloroform (2.2.4).

Rinse the solution with chloroform previously dehydrated with sodium carbonate and proceed as for (a) (Carr-Price reaction).

Pass the chloroform layer through a cotton-wool filter previously cleaned and wetted with chloroform into a graduated flask (2.2.12).

Quantitatively transfer the solution into a separating funnel (5.2) and extract the aqueous solution twice with 20-ml portions of chloroform (4.2).

Carr-Price reaction: Remove the benzene from the column by washing three times with chloroform previously dehydrated by means of potassium carbonate.

Add exactly 100 ml of diethyl ether (3.1) and 50 ml of chloroform (3.2) and then, using a graduated pipette, 10 ml of sodium hydroxide solution (3.3).

After phase separation, run the chloroform layer into a second separating funnel, containing 110 ml of deionised water and 5 ml of acidic methylene blue solution (2.2.3).

Pipette exactly 5 ml of internal standard solution (4.6) into a 10-ml standard flask and add about 300 mg (M1 mg) of chloroform, accurately weighed.

Carr-Price reagent: stir approximately 25 g antimony trichloride a.p. (kept in a desiccator) with 100 ml chloroform (3.15) until the solution is saturated.

The method is based on the fact that the cationic dye methylene blue forms blue salts with anionic surfactants (MBAS), which can be extracted with chloroform.

Measure the height and the width at half height of the acetonitrile and chloroform peaks and calculate the area of both peaks, using the formula: height × width at half height.

For a chloroform content of about 3 %, the difference between the results of two determinations in parallel carried out on the same sample should not exceed an absolute value of 0 73 %.

Filter the combined chloroform extracts through the same cotton wool filter and dilute to the mark in the 50 ml flask (2.2.12) with chloroform used for rewashing the cotton wool.

The bixin cannot be eluted in benzene, light petroleum, ether, chloroform, acetone, etharol or methanol. But the ethanol and methanol cause the orange tint to turn into an orange yellow.

Weigh to the nearest mg a sample of not more than 10 g containing not more than 80 mg of theobromine, place in a 500 ml flat-bottomed flask with a ground-glass stopper and add 270 ml of chloroform (3.1) and 10 ml of ammonia (3.2).

Shake 25 mg of riboflavin with 10 ml of ethanol-free chloroform for five minutes, then filter: the colour of the filtrate should not be more intense than that of an aqueous solution obtained by diluting 3 ml of 0 71 N potassium dichromate to 1000 ml.

whereas the laying down of methods for the sampling, laboratory preparation, identification and determination of free sodium and potassium hydroxides, the identification and determination of oxalic acid and alkaline salts thereof in hair care products, the determination of chloroform in toothpastes and of zinc, and the identification and determination of phenolsulfonic acid constitutes a first step in this direction;

By way of derogation from Article 3 and Annex II of Directive 86/280/EEC, the limit value for discharges of chloroform into the waters referred to in Article 1 of Council Directive 76/464/EEC on pollution caused by certain dangerous substances discharged into the aquatic environment of the Community fn shall not apply in Malta until 30 September 2004 to Marsa and Delimara power plants, until 31 December 2004 to Ras il-Hobż outfall, until 31 December 2006 to Ic-Cumnija outfall and until 31 March 2007 to Wied Ghammieq outfall.

By way of derogation from Article 3 and Annex II of Directive 86/280/EEC, the limit value for discharges of chloroform into the waters referred to in Article 1 of Council Directive 76/464/EEC on pollution caused by certain dangerous substances discharged into the aquatic environment of the Community fn shall not apply in Malta until 30 September 2004 to Marsa and Delimara power plants, until 31 December 2004 to Ras il-HobĹĽ outfall, until 31 December 2006 to Ic-Cumnija outfall and until 31 March 2007 to Wied Ghammieq outfall.

Chloroform/Diethyl ether, 66:33 (v/v)

l, 1,1-Trichloroethane (Methyl chloroform)

Chloroform, analytical purity.

Make up to the mark with chloroform (4.3) and shake.

pentyl chloroformate

If 'c' represents the internal standard, chloroform or 2,4-dimethylheptane:

If 'c' represents the internal standard, chloroform or 2,4-dimathylheptane:

As examples the following response factors have been obtained (for chloroform:k=l):

Chloroform, analytical reagent quality, freed from oxygen by bubbling a current of pure, dry inert gas through it.

Chloroform (4.1), 35 % (m/m).

Ethyl acetate (4.2.1.9), chloroform (4.2.1.10), diisopropyl ether (4.2.1.11), acetic acid (4.2.1.13) (20:

ethyl chloroformate C 3 H 5 ClO 2

Add 10 ml of chloroform (6.1).

3- chloroformyl- o- tolyl acetate

methyl chloroformate C 2 H 3 ClO 2

Aa = the area of the chloroform peak,

Chloroform reference solution

(S)- alpha- chloroformylethyl acetate