GB/T 39183-2020 English PDF (GBT39183-2020)

method for the determination of the migration quantity of N-nitrosamines and nitrosatable substances in consumer products. This Standard applies to elastomer materials such as latex, rubber, PVC that can be in oral contact in consumer products.

GB/T 39183-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 13.120
Y 57
Determination of the migration quantity of
nitrosamines in consumer products -
Gas chromatography-tandem mass spectrometry
ISSUED ON: OCTOBER 21, 2020
IMPLEMENTED ON: OCTOBER 21, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of the PRC.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Principle ... 4
4 Reagents or materials ... 4
5 Apparatus ... 6
6 Samples ... 6
7 Analytical procedure ... 7
8 Data processing ... 10
9 Method quantification limit ... 11
10 Recovery rate and precision ... 11
11 Test report ... 11
Appendix A (Normative) Chromatography-mass spectrometry analysis
parameters of N-nitrosamines ... 13
Appendix B (Informative) MRM chromatogram of N-nitrosamine standard
substances ... 14
Appendix C (Informative) Statistical data of precision test obtained from laboratory ... 15
Determination of the migration quantity of
nitrosamines in consumer products -
Gas chromatography-tandem mass spectrometry
1 Scope
This Standard specifies the gas chromatography-tandem mass spectrometry method for the determination of the migration quantity of N-nitrosamines and nitrosatable substances in consumer products.
This Standard applies to elastomer materials such as latex, rubber, PVC that can be in oral contact in consumer products.
2 Normative references
The following documents are indispensable for the application of this document. For the dated references, only the editions with the dates indicated are applicable to this document. For the undated references, the latest edition (including all the amendments) are applicable to this document.
GB/T 6682 Water for analytical laboratory use - Specification and test
methods
3 Principle
USE artificial saliva to migrate and extract the sample. The migration solution is purified and concentrated by solid-phase extraction; then determined by gas chromatograph-triple quadrupole tandem mass spectrometer (GC-MS/MS).
USE multiple reaction monitoring mode (MRM) for qualitative and external standard quantification.
4 Reagents or materials
Unless otherwise specified, only analytically pure reagents are used. The water is the grade 1 water specified in GB/T 6682.
4.1 Sodium bicarbonate.
4.2 Sodium chloride.
5 Apparatus
5.1 Gas chromatograph-triple quadrupole mass spectrometer, equipped with electron bombardment ionization source (EI source).
5.2 Nitrogen blowing instrument.
5.3 Analytical balance: Accuracy is 0.1 mg and 0.01 g.
5.4 Constant-temperature water bath: The temperature is (40±2)°C.
5.5 Solid-phase extraction device: Equipped with a vacuum pump.
5.6 Solid-phase extraction column: Porous polystyrene-divinylbenzene
copolymer small column (specification is 500 mg, 6 mL); or equivalent. If other solid-phase extraction columns are used, it shall ensure that the target substance has a good recovery rate.
Note: It has been verified by experiments that, the solid-phase extraction column of porous polystyrene-divinylbenzene copolymer small column type is suitable for the enrichment and purification of 15 N-nitrosamines involved in this Standard; for reference only.
5.7 Organic filter membrane: Pore size is 0.22 μm.
5.8 Brown volumetric flask: The capacity is 10 mL, 50 mL, 100 mL.
5.9 Brown conical flask with stopper: The capacity is 50 mL and 100 mL. 5.10 Glass beads: The diameter is 5 mm~7 mm.
6 Samples
6.1 Light-proof requirements
The entire sample treatment and analysis process shall be carried out under dark conditions, to prevent the photodegradation of N-nitrosamines.
6.2 Sample preparation
6.2.1 Samples with short oral contact time
For samples with short oral contact time (such as balloons), cut the sample to be tested; WEIGH 5 g (accurate to 0.01 g) into a 100 mL conical flask with stopper. ADD 45 mL of artificial saliva and a few glass beads; CLOSE the lid; SHAKE gently to ensure that the sample is completely infiltrated by the Solution A (or solution B) passes through the column at a flow rate of about 1 mL/min. After loading the sample, drain it for 5 min. USE 6 mL of ethyl acetate (4.7) to elute twice (3 mL each time); COLLECT the eluent; USE anhydrous sodium sulfate (4.5) to remove the water in the eluent. USE a slow stream of nitrogen to blow the supernatant to near dryness; USE ethyl acetate (4.7) to dilute to 1 mL. After the sample solution is shaken well, filter it through a 0.22 μm organic filter membrane (5.7); PUT into a brown injection vial and test it on the machine immediately. If it cannot be tested in time, it shall be stored under freezing and dark conditions. The test shall be completed as soon as possible within two days.
7.3 Determination conditions of gas chromatography-tandem mass
spectrometry
The test results depend on the apparatus used. It is impossible to give general parameters for chromatographic analysis. The following parameters have been proven to be feasible:
a) Chromatographic column: 5% phenyl and 95% dimethyl polysiloxane low- loss silica capillary column (30 m×0.25 mm×0.25 μm); or equivalent.
b) Column temperature: The initial column temperature is 50 °C; KEEP it for 3 min. At a rate of 30 °C/min, raise the temperature to 80 °C and keep it for 7 min. At a rate of 20 °C/min, raise the temperature to 130 °C. At a rate of 40 °C/min, raise the temperature to 210 °C. At a rate of 10 °C/min, raise the temperature to 240 °C and keep it for 5 min.
c) Temperature of injection port: 260 °C.
d) Ion source temperature: 180 °C.
e) Transmission line temperature: 250 °C.
f) Carrier gas: Helium (purity≥99.999%); flow rate: 1.0 mL/min.
g) Ionization method: EI ionization.
h) Ionization energy: 70 eV.
i) Injection method: Splitless injection.
j) Injection volume: 1 μL.
k) Collision gas: Argon (purity≥99.999%).
l) Data acquisition mode: Multiple reaction monitoring (MRM). The analysis parameters of each substance are shown in Appendix A.
f - Dilution factor;
m - The weighing amount of the sample (6.2), in grams (g);
wNA - The mass concentration of N-nitrosamine in the sample [formula (1)], in micrograms per kilogram (μg/kg).
The calculation result is expressed to one decimal place. When the result exceeds 100 μg/kg, it is expressed to the ones place.
9 Method quantification limit
The quantification limit of this method for N-Nitroso-methyl-ethylamine and N- nitrosodiisopropylamine is 0.025 μg/kg. The quantitation limit for N-nitroso-N- methyl-N-phenylamine, N-nitrosodiisobutylamine, N-Nitrosodicyclohexylamine and N-nitrosodibenzylamine is 0.125 μg/kg. The quantification limit for the remaining analytes is 0.05 μg/kg.
10 Recovery rate and precision
10.1 Recovery rate
Within the added concentration of 0.1 μg/kg~50 μg/kg, the recovery rate for N- nitrosodimethylamine is 55%~85%; the recovery rate for other N-nitrosamines is 80%~110%.
10.2 Precision
In different laboratories, according to the same test method, different operators use different equipment to perform independent tests on the same sample. The absolute difference between the two independent measurement results
obtained shall not be greater than 15% of the arithmetic mean of the two measurement values. The premise is that 15% greater than the arithmetic mean of the two measurement values shall not exceed 5%. Refer to Appendix C for the statistical data of precision test obtained from the laboratory.
11 Test report
The test report shall give at least the following:
a) Sample description;
b) Standard used (including issuance or publication year number);