BS/EN 71-7-2014 pdf download.Safety of toys Part 7 : Finger paints-Requirements and test methods.
D.1 General
For the detection of certain azo colourants, the sample is treated with sodium dithionite in a citrate buffer (pH 6) at 70 °C in a sealed vessel. Upon reductive cleavage, the resultant amines are extracted with MTBE by means of a “kieselguhr” type SPE column. e.g. Chromabond® XTR, or equivaientl). The ether extract is carefully concentrated with a rotary evaporator or an equivalent sample concentrator and the residue is dissolved in acetonitnie or other suitable solvent, depending upon the detection/determination procedure to be used.
The detection/determination of amines resulting either from the reductive cleavage method or already present in the sample as free primary aromatic amines is performed by high performance liquid chromatography with a diode-array detector (HPLCIDAD) or by capillary gas chromatography with mass-selective detector (GC-MS).
The amines shall be identified by at least one of the chromatographic separation techniques described in this annex. Unless an unequivocal identification is achieved (e.g. by using GC-MS and comparing retention times with known standards), confirmation of positive results shall be achieved by a suitable alternative separation technique (to avoid possible misinterpretation from, for example, isomers of the amines to be identified).
NOTE 1 Some amines may be thermally unstable and cannot be determined by gas chromatography.
The quantification of the amines is performed by H PLC/DAD or GC-MS.
NOTE 2 Some of the amines are deaved under the reductive conditions In D.6.2 according to Table D.1:
4-Aminoazobenzene is reductively cleaved to p-phenylenediamine and aniline; o-aminoazotoluene is reductively cleaved to 2-methyl-p-phenylenediamine and o-toluidine; and 2-Amino-4-nitrotoluene is reduced to 4-methyl-m-phenylenediamine.
A p-ohibited azo colourant is deemed to be present in the finger paint if, on reductive cleavage, one or more of the amines listed in Tables 1 and 2 is present in a concentration exceeding 30 mg/kg.
Each primary aromatic amines listed in Table 1 is deemed to be determinable at levels exceeding 5 mg/kg.
0.2.3 tert-Butyl methyl ether (MTBE)
D.2.4 Citrate/sodium hydroxide buffer, c(trisodium citrate) = 0,06 molIl, pH 6. preheated to 70 °C or 37 °C:
Dissolve 12.6 g citric add monohydrate and 6,4 g sodium hydroxide in 900 ml water. Adjust the volume to I L. NOTE ‘Ready-for-use solution, Merck-Nr. 1.09437, has been found suitable2).
D.2.5 Sodium dithicnite solution, freshly dissolved in water. p = 200 mg/mI
D.2.6 Porous, granular ukieseIguhr SPE column
NOTE Chromabond® XTR has been found suitable2).
0.2.7 Anhydrous sodium sulphate
0.2.8 Certified amine standards, primarily those listed in Tables 1 and 2
NOTE The amines in Tables 1 and 2 are human carcinogens or cancer suspect agents (Cat. 1A and 1B), The handling of these chemicals requires the utmost care and commensurate safety measures.
0.2.9 Internal standards (IS) for gas chromatography
0.2.9.1 IS 1: 2,4,5-Trichloroaniline, CAS No. 636-30-6
0.2.9.2 IS 2: 4-Amino-2-methylquinoline, CAS No. 6628-04-2
D.2.93 IS 3: Tributylphosphate. CAS No. 126-73-8
0.2.10 Standard solutions
D.2.10.1 Stock solution of aromatic amiries
Prepare a stock solution containing 100 mg/I of each aromatic amine (0.2.8) In methanol (0.2.1). This solution shall be stored in the absence of light at (—18 ± 2) °C.
0.2.10.2 Calibration solutions
Prepare six calibration solutions in the range 0,1 mg/I to 5,0 mg/I by dilution of the aromatic amines stock solutions (D.2.10.1) into (100±0.1) ml volumetric flasks using MBTE (0.2.3). Before making up to the final volume, add 0,1 ml of internal standard (D.2.10.3) to each calibration solution in order to obtain a final internal standard concentration of 1 mg/I, The calibration solutions are ready for GC-MS analysis.
D.2.10.3 Internal standard solution
Prepare a stock solution of each internal standard (0.2.9.1 to 0.2.9.3) at 10,0 mgil in methanol (D.2.1).
0.2.10.4 Recovery solution of aromatic amines
Prepare a recovery solution containing 10 mgI) of each aromatic amine (D.2.10.1) in methanol (D.2.1). This solution shall be stored in the absence of light at (—18 ± 2) C.
The stability of all calibration solutions should be checked regularly. These should be stable for up to 6 months when stored in the dark at (—18 ± 2) °C.
NOTE The solvent used will depend on the chromatographic method chosen for analysis.
D.3 Apparatus
Ordinary laboratory equipment, and
D.3.1 50 ml conical flask of temperature-resistant glass with tight-fitting cap
0.3.2 Water bath, capable of maintaining a temperature of (37 ± 2) C and (70 ± 2) C.
0.3.3 Column made from glass or polypropylene, 25 mm to 30 mm internal diameter, 140 mm to 150mm length. filled with about 20 g porous, granular kieselguhr’ SPE material, fitted on the outlet with a glass fibre filter (or commercial SPE column).
NOTE Chromabond® XTR (Macherey-Nagel Catalogue No. 730 507) has been found sLMtable3).
D.3,4 Vacuum rotary evaporator or equivalent low temperature sample concentration system
D.3.5 Pipettes 10 ml, 5 ml, 2 ml, 1 ml
D.4 Instrumentation
The analysis shall be performed using equipment selected from the following list
D.4.1 HPLC with gradient-elution and DAD
0.4.2 GC with MS
D.5 Sampling procedure
Homogenize the sample by stirring thoroughly.BS/EN 71-7-2014 pdf download.