Determination of 11 industrial dyes including auramine O in soybean products
1 Scope
The method provides a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the determination of disperse orange 11, disperse orange 1, disperse orange 3, disperse orange 37, disperse yellow 3, methyl yellow, ethyl yellow, basic orange 22, basic orange 21, auramine O and Sudan orange G in soybean products.
The method is suitable for the qualitative confirmation and quantitative determination of disperse orange 11, disperse orange 1, disperse orange 3, disperse orange 37, disperse yellow 3, methyl yellow, ethyl yellow, basic orange 22, basic orange 21, auramine O and Sudan orange G in tofu, tofu skin, dried beancurd sticks, fried tofu skin and fried bean curd.
2 Principle
Eleven dyes in the sample, including auramine O, are extracted by acetonitrile and centrifuged. The supernatant is purified by dispersed solid-phase extraction, detected by HPLC-tandem mass spectrometer, and quantified by external standard method.
3 Reagents and materials
Unless otherwise stated, reagents used in the method are analytically-pure reagents, and the water is Class-I water as specified in GB/T 6682.
0.1% aqueous formic acid solution (containing 5mmol/L ammonium acetate): dissolve 0.385g of ammonium acetate (3.1.2) in an appropriate amount of water, then add 1mL of formic acid (3.1.3), and dilute to 1,000mL with water.
3.3 Standard
The Chinese name, English name, CAS number, molecular formula, and relative molecular mass of the standards including disperse orange 11, disperse orange 1, disperse orange 3, disperse orange 37, disperse yellow 3, methyl yellow, ethyl yellow, basic orange 22, basic orange 21, auramine O and Sudan orange G are detailed in Table A.1 of Annex A, and their purity is greater than or equal to 90%.
3.4 Preparation of standard solution
3.4.1 Standard stock solution (1mg/mL): accurately weigh 10mg (accurate to 0.01mg) of standard (3.3), dissolve it in acetonitrile (3.1.1) to a volume of 10mL, and prepare a standard stock solution with a mass concentration of 1mg/mL. Preserve the solution at 0℃to 4℃ for 3 months.
Note: When preparing the standard stock solution, care shall be taken to convert the purity of the standard into the concentration of the reserve solution.
3.4.2 Mixed standard intermediate solution (50ng/mL): accurately pipette 0.05mL of the standard stock solutions (3.4.1) of each component respectively, put them into a 100mL volumetric flask, dilute to the scale with acetonitrile (3.1.1), and shake well and dilute to the scale. Precisely pipette 1.0mL of the above mixed standard solution into a 10mL volumetric flask, set the volume to the scale with acetonitrile (3.1.1), shake well, and prepare a mixed standard intermediate solution with a mass concentration of 50ng/mL. Preserve the solution at 0℃ to 4℃ in a dark place, with a preserve time of one week.
3.4.3 Mixed standard working solution: take six 5mL volumetric flasks, add 0mL, 0.02mL, 0.05mL, 0.10mL, 0.5mL and 1.0mL of mixed standard intermediate solution (50ng/mL) (3.4.2) in turn, and dilute with blank sample extract (5.3) to the scale, and then follow the rest operations as specified in 5.2.2 to prepare into series standard working solutions in which the mass concentration of each component is 0ng/mL, 0.2ng/mL, 0.5ng/mL, 1.0ng/mL, 5.0ng/mL and 10.0ng/mL respectively. The solution shall be freshly prepared before use.
1 Scope 2 Principle 3 Reagents and materials 4 Apparatus 5 Analysis steps 6 Calculation of results 7 Precision 8 Others Annex A (Informative) Chinese name, English name, CAS number, molecular formula and relative molecular mass of the standards Annex B (Informative) Reference conditions for mass spectrometry Annex C (Informative) Multi-reaction monitoring (MRM) chromatograms of standard solution
Determination of 11 industrial dyes including auramine O in soybean products
1 Scope
The method provides a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the determination of disperse orange 11, disperse orange 1, disperse orange 3, disperse orange 37, disperse yellow 3, methyl yellow, ethyl yellow, basic orange 22, basic orange 21, auramine O and Sudan orange G in soybean products.
The method is suitable for the qualitative confirmation and quantitative determination of disperse orange 11, disperse orange 1, disperse orange 3, disperse orange 37, disperse yellow 3, methyl yellow, ethyl yellow, basic orange 22, basic orange 21, auramine O and Sudan orange G in tofu, tofu skin, dried beancurd sticks, fried tofu skin and fried bean curd.
2 Principle
Eleven dyes in the sample, including auramine O, are extracted by acetonitrile and centrifuged. The supernatant is purified by dispersed solid-phase extraction, detected by HPLC-tandem mass spectrometer, and quantified by external standard method.
3 Reagents and materials
Unless otherwise stated, reagents used in the method are analytically-pure reagents, and the water is Class-I water as specified in GB/T 6682.
3.1 Reagents
3.1.1 Acetonitrile (CH3CN): chromatographically pure.
3.1.2 Ammonium acetate (CH3COONH4): chromatographically pure.
3.1.3 Formic acid (HCOOH): guaranteed reagent.
3.1.4 Anhydrous sodium sulfate (Na2SO4).
3.2 Preparation of reagents
0.1% aqueous formic acid solution (containing 5mmol/L ammonium acetate): dissolve 0.385g of ammonium acetate (3.1.2) in an appropriate amount of water, then add 1mL of formic acid (3.1.3), and dilute to 1,000mL with water.
3.3 Standard
The Chinese name, English name, CAS number, molecular formula, and relative molecular mass of the standards including disperse orange 11, disperse orange 1, disperse orange 3, disperse orange 37, disperse yellow 3, methyl yellow, ethyl yellow, basic orange 22, basic orange 21, auramine O and Sudan orange G are detailed in Table A.1 of Annex A, and their purity is greater than or equal to 90%.
3.4 Preparation of standard solution
3.4.1 Standard stock solution (1mg/mL): accurately weigh 10mg (accurate to 0.01mg) of standard (3.3), dissolve it in acetonitrile (3.1.1) to a volume of 10mL, and prepare a standard stock solution with a mass concentration of 1mg/mL. Preserve the solution at 0℃to 4℃ for 3 months.
Note: When preparing the standard stock solution, care shall be taken to convert the purity of the standard into the concentration of the reserve solution.
3.4.2 Mixed standard intermediate solution (50ng/mL): accurately pipette 0.05mL of the standard stock solutions (3.4.1) of each component respectively, put them into a 100mL volumetric flask, dilute to the scale with acetonitrile (3.1.1), and shake well and dilute to the scale. Precisely pipette 1.0mL of the above mixed standard solution into a 10mL volumetric flask, set the volume to the scale with acetonitrile (3.1.1), shake well, and prepare a mixed standard intermediate solution with a mass concentration of 50ng/mL. Preserve the solution at 0℃ to 4℃ in a dark place, with a preserve time of one week.
3.4.3 Mixed standard working solution: take six 5mL volumetric flasks, add 0mL, 0.02mL, 0.05mL, 0.10mL, 0.5mL and 1.0mL of mixed standard intermediate solution (50ng/mL) (3.4.2) in turn, and dilute with blank sample extract (5.3) to the scale, and then follow the rest operations as specified in 5.2.2 to prepare into series standard working solutions in which the mass concentration of each component is 0ng/mL, 0.2ng/mL, 0.5ng/mL, 1.0ng/mL, 5.0ng/mL and 10.0ng/mL respectively. The solution shall be freshly prepared before use.
3.5 Materials
3.5.1 N-primary secondary amine (PSA): 40μm~100μm.
3.5.2 Octadecylsilane chemically bonded silica (C18): 40μm~100μm.
3.5.3 QuEChERS purified powder: each portion contains 50mg of PSA (3.5.1), 50mg of C18 (3.5.2) and 100mg of MgSO4.
3.5.4 Microporous filter membrane (PVDF): 0.22μm, aqueous phase.
Contents of BJS 202204
1 Scope
2 Principle
3 Reagents and materials
4 Apparatus
5 Analysis steps
6 Calculation of results
7 Precision
8 Others
Annex A (Informative) Chinese name, English name, CAS number, molecular formula and relative molecular mass of the standards
Annex B (Informative) Reference conditions for mass spectrometry
Annex C (Informative) Multi-reaction monitoring (MRM) chromatograms of standard solution
