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National Food Safety Standard
Determination of Polycyclic Aromatic Hydrocarbons in Foods
1 Scope
This standard specifies the liquid chromatography for the determination of polycyclic aromatic hydrocarbons (naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno [1,2,3-c,d] pyrene, dibenzo[a,h] anthracene and benzo[g,h,i]perylene) in foods and the gas chromatography-mass spectrometry for the determination of polycyclic aromatic hydrocarbons (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenzo[a,h]anthracene and benzo [g,h,i]perylene) in foods.
This standard is applicable to the determination of polycyclic aromatic hydrocarbon content in foods.
Method I High Performance Liquid Chromatography
2 Theory
Extract polycyclic aromatic hydrocarbons in the specimen with organic solvent, concentrate the extract solution to nearly dry, dissolve it with solvent and purify the solution with PSA (N-propyl ethylene diamine) and C18 solid-phase extraction filler or with magnesium trisilicate solid-phase extraction column. Concentrate it to the scale, then separate it by high performance liquid chromatography, determine the fluorescence intensity of polycyclic aromatic hydrocarbons at different excitation wavelengths and emission wavelengths, and then quantify it through external standard method.
3 Regents and Materials
Unless otherwise specified, analytically pure reagents and Grade 1 water (specified in GB/T 6682) are adopted for the purposes of this method.
3.1 Regents
3.1.1 Acetonitrile (CH3CN): chromatographically pure.
3.1.2 N-hexane (C6H14): chromatographically pure.
3.1.3 Methylene dichloride (CH2Cl2): chromatographically pure.
3.1.4 Diatomite: chromatographically pure.
3.1.5 Magnesium sulfate (MgSO4): Guaranteed reagent.
3.1.6 N-Propyl ethylene diamine (PSA): with particle size of 40μm.
3.1.7 End-capping C18 solid-phase extraction filler: with particle size of 40μm~63μm.
3.1.8 Magnesium trisilicate solid-phase extraction column: 500mg, 3mL.
3.1.9 Organic-phase microporous filter membrane: 0.22μm.
3.2 Preparation of regents
3.2.1 N-hexane-methylene chloride mixed solution (1+1): measure 500mL of methylene chloride, add 500mL of n-hexane and mix them well.
3.2.2 Acetonitrile saturated n-hexane: measure 200mL of acetonitrile, add 800mL of n-hexane, mix them well by shaking and then keep the solution still for layering; the upper n-hexane layer is acetonitrile saturated n-hexane.
3.3 Standards
Store polycyclic aromatic hydrocarbons (the certified standard solution (200μg/mL) of naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenzo[a,h]anthracene and benzo[g,h,i] perylene) below -18℃.
Warning——polycyclic aromatic hydrocarbons are the known carcinogenic, teratogenic and mutagenic substances, and the carcinogenicity increases with increasing of benzene ring, therefore, pay special attention to safety protection during determination. The personnel shall conduct the determination in a fume hood and wear a pair of gloves to minimize exposure.
3.4 Preparation of standard solutions
3.4.1 The standard intermediate solution of polycyclic aromatic hydrocarbons (1,000ng/mL): pipet 0.5mL of polycyclic aromatic hydrocarbon standard solution and scale the volume to 100mL with acetonitrile. Store it below -18℃.
3.4.2 The standard series working solutions of polycyclic aromatic hydrocarbons: respectively pipet 0.10mL, 0.50mL, 1.0mL, 2.0mL, 5.0mL and 10.0mL of standard intermediate solution of polycyclic aromatic hydrocarbons, then scale the volume to 100mL with acetonitrile to obtain standard series working solutions with mass concentration of 1ng/mL, 5ng/mL, 10ng/mL, 20ng/mL, 50ng/mL and 100ng/mL respectively.
4 Apparatuses
4.1 High performance liquid chromatograph, equipped with fluorescence detector.
4.2 Electronic balance: with a sensitivity of 0.01g.
4.3 Refrigerated centrifuge: with rotating speed ≥4,500r/min.
4.4 Vortex oscillator.
4.5 Ultrasonic oscillator.
4.6 Disintegrator.
4.7 Homogenizer.
4.8 Nitrogen evaporator.
4.9 Rotary evaporator.
1 Scope
2 Theory
3 Regents and Materials
4 Apparatuses
5 Analytical Procedures
6 Expression of Analysis Results
7 Precision
8 Others
9 Theory
10 Reagents and Materials
11 Apparatuses
12 Analytical Procedures
13 Expression of Analysis Results
14 Precision
15 Others
Annex A Liquid Chromatogram of Standard Solution of Polycyclic Aromatic Hydrocarbons
Annex B Gas Chromatography - Mass Spectrometry Total Ion Chromatography of Standard Solution of Polycyclic Aromatic Hydrocarbons
