GB/T 5009.191-2003 Determination of 3-chloro-1,2-propanediol content in foods

This standard specifies the method for determining the residual amount of 3-chloro-1,2-propanediol (3-MCPD) in food. This standard is applicable to the determination of 3-chloro-1,2-propanediol content in hydrolyzed vegetable protein liquid, condiments, sausages, cheese, fish, flour, starch, cereals and bread. The determination limit of this standard is 5μg/kg. The linear range of this standard is 0.005ng～0.600ng. GB/T 5009.191-2003 Determination of 3-chloro-1,2-propanediol content in food GB/T5009.191-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of China
GB/T5009.191—2003
Determination of 3-monochloro-1,2-propane-diol in foodsIssued on August 11, 2003
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
Implementation on January 1, 2004
GB/T5009.191-—2003
This standard is modified by adopting the International Association of Analytical Chemists (AOAC Int) method AOAC2000.01 "Determination of 3-monochloropropane-1,2-diol in food ingredient using mass spectrometric detection" (English version 2000). The main difference between this standard and AOAC2000.01 is that the determination limit of this standard method is 5μg/kg + the determination limit of AOAC2000.01 is 10μg/kg.
This standard is proposed by the Ministry of Health of the People's Republic of China. This standard is under the jurisdiction of the Food Hygiene Supervision and Inspection Institute of the Ministry of Health. The drafting units of this standard are: Institute of Nutrition and Food Hygiene, Chinese Academy of Preventive Medicine, Beijing Center for Disease Control and Prevention, Jiangsu Center for Disease Control and Prevention, Chongqing Center for Disease Control and Prevention. The main drafters of this standard are Wu Yongning, Zhao Yunfeng, Zhao Jingling, Tu Xiaoming, Ma Yongjian, Zhao Jian, and Li Jingguang. 513
GB/T5009.191—2003
3-Chloro-1,2-propanediol (3-monochloro-1,2-propane-diol, 3-MCPD) is an internationally recognized food contaminant. The main source of aziridine pollution comes from acid hydrolyzed vegetable protein (HVP), which is produced by residual triglycerides or glycerol chlorination. Including monosubstituted 3-fluoro-1,2-propanediol (3-MCDP) and 2-nitro-1,3-propanediol (2-MCDP) and dichloro-substituted 1,3-dioxy-2-propanol (1,3-DCP) and 2,3-chloro-1-propanediol (2,3-DCP). They are not only carcinogenic, but also have the effect of inhibiting sperm activity. The Codex Alimentarius Committee on Food Additives and Contaminants (CCFAC) also included it in the standard-setting agenda. In June 2001, the 57th meeting of the Joint Expert Committee on Food Additives (JECFA) of WHO/FAO evaluated the dangers of 3-MCPD and finally proposed a provisional maximum tolerable daily intake (PMTDI) of 2μg/kg body weight for 3-MCPD based on the most sensitive renal toxicity, and believed that the intake of soy sauce with the current contamination level may cause health hazards. For this reason, many countries have established maximum allowable limit standards to control the contamination level of 3-MCDP in food. my country has also formulated the maximum allowable limit standard of hydrolyzed protein seasoning liquid, and the maximum allowable limit standard of other foods (especially soy sauce and food cool) is also being formulated. However, my country does not have a national standard determination method that is compatible with it so far. The detection method of 3-MCPD in the world requires the most sensitive detection means to reach the lowest possible level technically, and recommends the use of stable isotopes as quantitative internal standards to improve the accuracy of the analysis result. The scientific center laboratory (CSL) of the Ministry of Agriculture, Fisheries and Food (MAFF) of the United Kingdom adopts the isotope dilution technology of 3-MCPD substituted isotope (d-3-MCPD), takes heptafluorobutyryl imidazole as a derivatization reagent, and detects 3-MCPD with gas chromatography-mass spectrometry. After the international synergy test of 12 laboratories in 6 countries, this method was adopted by the International Association of Analytical Chemists (AOACInt), as the formal method (method number AOAC2000.01) for checking 3-MCPD. In order to ensure the applicability of this method to my country, this standard has been proposed by contrast verification. The determination method of this standard is modified to adopt the AOAC2000.01 method. The sensitivity of the method meets the international requirements for trace detection of 3-MCPD in food and can meet the monitoring needs of 3-MCPD in food in my country. 514
1 Scope
Determination of 3-chloro-1,2-propanediol content in food This standard specifies the determination method of 3-oxo-1,2-propanediol (3-MCPD) residues in food. GB/T5009.191—2003
This standard is applicable to the determination of 3-chloro-1,2-propanediol content in hydrolyzed vegetable protein liquid, condiments, sausages, cheese, fish, flour, starch, cereals and bread.
The determination limit of this standard is 5pg/kg. The linear range of this standard is 0.005ng~0.600ng. 2 Principle
This standard adopts isotope dilution technique and uses d5-3-MCPD as internal standard for quantitative analysis. Internal standard solution is added to the sample, diatomaceous earth (ExtrelutTM20) is used as adsorbent, column chromatography is used for separation, non-polar lipid components in the sample are eluted with n-hexane-ether (9+1), 3-MCPD in the sample is eluted with ether, and heptafluorobutyrylimidazole (HFBI) solution is used as derivatization reagent. Quantitative analysis is performed using mass spectrometry scanning mode of selected ion monitoring (SIM), and quantitative analysis is performed using internal standard method. 3 Reagents and materials
Unless otherwise specified, only reagents determined to be analytically pure and distilled water or water of equivalent purity are used in the analysis. 3.1 2,2,4-Trimethylpentane.
3.2 Ether.
3.3 n-hexane.
3.4 ​​Sodium chloride.
3.5 Anhydrous sodium sulfate.
3.6 ExtrelutTM20, or equivalent diatomaceous earth. 3.7 Heptafluorobutyrylimidazole.
3.8 3-Fluoro-1,2-propanediol standard (3-MCPD), purity>98%. 3.9 d5-3-Chloro-1,2-propanediol standard (d5-3-MCPD), purity>98%. 3.9 Saturated sodium fluoride solution (5mol/L): Weigh 290g sodium nitride, dissolve in water and dilute to 1000mL. 3.10 n-hexane-ether (9+1): Measure 100mL ether, add 900mL n-hexane and mix well. 3.113-MCPD standard stock solution (1000mg/L): Weigh 25mg of 3-MCPD (accurate to 0.01mg), place in a 25mL volumetric flask, add n-hexane to dissolve, and dilute to scale. 3.123-MCPD intermediate solution (100mg/L): Accurately pipette 10mL of 3-MCPD stock solution, place in a 100mL volumetric flask, add n-hexane to dilute to scale.
3.133-MCPD series solutions: Accurately pipette an appropriate amount of 3-MCPD intermediate solution, place in a 25mL volumetric flask, add n-hexane to dilute to scale (concentrations are 0.00, 0.05.0.10.0.50, 1.002.00.6.00mg/L). 3.14 d5-3-MCPD stock solution (1000 mg/L): weigh 25 mg of d5-3-MCPD (accurate to 0.01 mg), place in a 25 mL volumetric flask, add ethyl acetate to dissolve, and dilute to scale. 3.15 d5-3-MCPD internal standard solution (10 mg/L): accurately transfer 1 mL of d5-3-MCPD stock solution, place in a 100 mL volumetric flask, add ethyl acetate to dilute to scale.
GB/T5009.191—2003
4 Instruments
4.1 Gas chromatograph-mass spectrometer (GC-MS). 4.2 Chromatographic column: DB-5ms column, 30 mX0.25 mm×0.25 μm, or equivalent capillary column. 4.3 Glass chromatography column: column length 40 cm, column inner diameter 2 cm. 4.4 Rotary evaporator.
Nitrogen evaporator.
Thermostatic box or other thermostatic heater.
Vortex mud mixer.
4.8 Gas-tight needle, 1mL
5 Analysis steps
5.1 Sample preparation
5.1.1 Liquid sample
Weigh 4.00g of sample, put it in a 100mL beaker, add 50μL of d5-3-MCPD internal standard solution (10mg/L), add 6g of saturated sodium chloride solution, and ultrasonicate for 15min. Www.bzxZ.net
5.1.2 Soup or solid and semi-solid plant hydrolyzed protein Weigh 4.00g of sample, put it in a 100mL beaker, add 50μL of d5-3-MCPD internal standard solution (10mg/L), add 6g of saturated sodium chloride solution, and ultrasonicate for 15min.
5.1.3 Sausage or cheese
Weigh 10 samples.00g, put it in a 100mL beaker, add 50μL of d5-3-MCPD internal standard solution (10mg/L), add 30g of saturated sodium chloride solution. Mix well, centrifuge (3500r/min) for 20min, and take 10g of supernatant. 5.1.4 Flour or starch or cereal or bread
Weigh 5.00g of sample, put it in a 100mL beaker, add 50μL of d5-3-MCPD internal standard solution (10mg/L), add 15g of saturated sodium nitride solution, and leave it overnight.
5.2 Sample extraction
Divide a bag of ExtrelutTM20 column filler into two parts, take one part and add it to the sample solution, mix well, and load the other part of the column filler into the chromatography column (fill the lower end of the chromatography column with glass wool). Load the mixture of sample and adsorbent into the chromatography column, and add 1cm of anhydrous sodium sulfate to the upper layer. After standing for 15 minutes, use 80 mL of n-hexane-ether (9+1) to elute the non-polar components and discard. Use 250 mL of ether to elute 3-MCPD (flow rate is about 8 mL/min). Add 15 g of anhydrous sodium sulfate to the collected ether, let stand for 10 minutes and filter. The filtrate is rotary evaporated to about 2 mL at 35°C, quantitatively transferred to a 5 mL stoppered test tube, and diluted to 4 mL with ether. Add a small amount of anhydrous sodium sulfate to the ether, shake, and stand for more than 15 minutes. 5.3 Derivatization
Pipette 1 mL of the sample solution, cover it in a 5 mL stoppered test tube, and blow it to near dryness with a nitrogen evaporator at room temperature, immediately add 1 mL of 2,2,4-trimethylpentane: add 0.05 mL of heptafluorobutyryl imidazole with a gas-tight needle, and immediately seal it. After vortex mixing, keep warm at 70°C for 20 minutes. After taking it out, let it cool to room temperature, add 3mL of saturated sodium chloride solution, vortex mix for 30s to separate the two phases. Take the organic phase and add about 0.3g of anhydrous sodium sulfate to dry. Transfer the solution to an automatic injection sample bottle for GC-MS determination. 5.4 Preparation of blank sample
Weigh 10mL of saturated sodium chloride solution (5mol/L), place it in a 100mL beaker, add 50μl of d5-3-MCPD internal standard solution (10mg/L), and ultrasonicate for 15min. The following steps are the same as the sample extraction and biochemical methods (5.2 and 5.3). 5.5 Preparation of standard series solutions
Pipette 0.1mL of each standard series solution, add 10μL of d5-3-MCPD internal standard solution (10mg/L), add 0.9mL of 2,2,4-trimethylpentane 516
GB/T5009.191—2003
, add 0.05mL of heptafluorobutyrylimidazole with a gas-tight needle, and immediately seal. The following steps are the same as the derivatization method of the sample (5.2 and 5.3).
5.6 Determination
5.6.1 Chromatographic conditions
Chromatographic column: DB-5ms column, 30mX0.25mmX0.25μm. Inlet temperature: 230℃.
Transmission line temperature: 250℃.
Program temperature: 50℃ for 1min, then increase to 90℃ at 2℃/min, then increase to 250℃ at 40℃/min, and maintain for 5min.
Carrier gas: red gas, column head pressure is 6psi.
Splitless injection, injection volume 1μL.
5.6.2 Mass spectrometry parameters
Ionization mode: electron impact source (EI), energy is 70eV. Ion source temperature is 200℃.
Analyzer (electron multiplier) voltage is 450V. Solvent delay is 12min, and mass spectrometry acquisition time is 12min~18min. Scanning method: Selected ion scanning (SIM) is used for acquisition. The characteristic ions of 3-MCPD are m/z253, 275, 289, 291 and 453, and the characteristic ions of d5-3-MCPD are m/z257, 294, 296 and 456. Select different ion channels, use m/z253 as the quantitative ion of 3-MCPD, m/z257 as the quantitative ion of d5-3-MCPD, and use m/z253, 275, 289, 291 and 453 as the qualitative identification ions of 3-MCPD. Investigate the intensity ratio of each fragment ion to the m/z453 ion. The requirement is that the intensity ratio of at least two of the four ions (m/z253, 275, 289 and 291) shall not exceed the same ion intensity ratio of the standard solution by ±20%. 5.6.3 Determination
Measure 1μL of the sample solution for injection. The retention time of 3-MCPD and d5-3-MCPD is about 16min. Record the peak areas of 3-MCPD and d5-3-MCPD. Calculate the peak area ratio of 3-MCPD (m/z253) and d5-3-MCPD (m/z257), and draw a standard curve with the injection amount (ng) of each series of standard solutions and the corresponding peak area ratio of 3-MCPD (m/z235) and d5-3-MCPD (m/z257). 5.7 Result calculation
Calculate the content of 3-chloro-1,2-propanediol in the sample by the internal standard method. See the following formula: X=Axf
Wherein,
X——3-nitrogen-1,2-propanediol content in the sample, in micrograms per kilogram (or micrograms per liter) [ug/kg (or ug/L)];A——3-nitrogen-1.2-propanediol mass corresponding to the peak area ratio of the sample chromatographic peak to the internal standard chromatographic peak, in nanogram (ng);——dilution factor of the sample solution
mThe sample volume, in grams (or milliliters) [g (or mL)]. The calculation result is expressed to three significant figures. 6 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 20% of the arithmetic mean. 517
GB/T5009.191—2003
7 Others
d5-3-MCPD.m/z257
14.39014.65514.994
3 -MCPD,m/z253
14.14314.38114.618
TTTTTTTTTT
FTTTTT
15.66216.06316.336| |tt||TTTTTTTTTTTT
Figure 13-Chloro-1,2-propanediol and its substituted isotopes Full scan total ion chromatogram 100
119147
3-MCPD
289327
341363413429453489498
ehamee
d5-3-MCPD
197,201
397413431456 464 496
t /hm/h:fjnnmhn/hmmrh/hgompap43m/z
Figure 23-Chloro-1,2-propanediol and its substituted isotope mass spectrum 100
d5-3MCPD,m/z257，294.296,45616.175
3-MCPD,m/z253，275，289291,453d5-3-MCPD,m/z257
3-MCPD,m/z253| |tt||Figure 3 Selective ion total ion chromatogram of 3-chloro-1,2-propanediol and its substituted isotopes 518
275.00289.00
3-MCPD
GB/T5009.191-—2003
mywym/2
d5-3-MCPD
mmmmrdm/z
Figure 4 Selected ion mass spectrum of 3-chloro-1,2-propanediol and its substituted isotopes 5192 Sample extraction
Divide a bag of ExtrelutTM20 column filler into two parts, take one part and add it to the sample solution, mix well, and load the other part of the column filler into the chromatography column (fill the lower end of the chromatography column with glass wool). Load the mixture of the sample and the adsorbent into the chromatography column, and add 1 cm of anhydrous sodium sulfate to the upper layer. After standing for 15 minutes, elute the non-polar components with 80 mL of n-hexane-ether (9+1) and discard. Elute 3-MCPD with 250 mL of ether (flow rate is about 8 mL/min). Add 15 g of anhydrous sodium sulfate to the collected ether, let it stand for 10 minutes and filter. Rotate and evaporate the filtrate at 35°C to about 2 mL, transfer quantitatively to a 5 mL stoppered test tube, and dilute to 4 mL with ether. Add a small amount of anhydrous sodium sulfate to the ether, shake, and let it stand for more than 15 minutes. 5.3 Derivatization
Pipette 1 mL of the sample solution, cover it in a 5 mL stoppered test tube, and blow it to near dryness with a nitrogen evaporator at room temperature, immediately add 1 mL of 2,2,4-trimethylpentane: add 0.05 mL of heptafluorobutyryl imidazole with a gas-tight needle, and immediately seal it. After vortex mixing, keep it at 70℃ for 20 minutes. After taking it out, put it at room temperature, add 3 mL of saturated sodium chloride solution, vortex mix for 30 seconds, and separate the two phases. Take the organic phase and add about 0.3 g of anhydrous sodium sulfate to dry. Transfer the solution to a sample bottle for automatic injection for GC-MS determination. 5.4 Preparation of blank sample
Weigh 10 mL of saturated sodium chloride solution (5 mol/L), place it in a 100 mL beaker, add 50 μl of d5-3-MCPD internal standard solution (10 mg/L), and ultrasonicate for 15 minutes. The following steps are the same as the sample extraction and biochemical methods (5.2 and 5.3). 5.5 Preparation of standard series solutions
Pipette 0.1mL of each standard series solution, add 10μL of d5-3-MCPD internal standard solution (10mg/L), add 0.9mL of 2,2,4-trimethylpentane 516
GB/T5009.191—2003
, add 0.05mL of heptafluorobutyrylimidazole with a gas-tight needle, and immediately seal. The following steps are the same as the derivatization method of the sample (5.2 and 5.3).
5.6 Determination
5.6.1 Chromatographic conditions
Chromatographic column: DB-5ms column, 30mX0.25mmX0.25μm. Inlet temperature: 230℃.
Transmission line temperature: 250℃.
Program temperature: 50℃ for 1min, then increase to 90℃ at 2℃/min, then increase to 250℃ at 40℃/min, and maintain for 5min.
Carrier gas: red gas, column head pressure is 6psi.
Splitless injection, injection volume 1μL.
5.6.2 Mass spectrometry parameters
Ionization mode: electron impact source (EI), energy is 70eV. Ion source temperature is 200℃.
Analyzer (electron multiplier) voltage is 450V. Solvent delay is 12min, and mass spectrometry acquisition time is 12min~18min. Scanning method: Selected ion scanning (SIM) is used for acquisition. The characteristic ions of 3-MCPD are m/z253, 275, 289, 291 and 453, and the characteristic ions of d5-3-MCPD are m/z257, 294, 296 and 456. Select different ion channels, use m/z253 as the quantitative ion of 3-MCPD, m/z257 as the quantitative ion of d5-3-MCPD, and use m/z253, 275, 289, 291 and 453 as the qualitative identification ions of 3-MCPD. Investigate the intensity ratio of each fragment ion to the m/z453 ion. The requirement is that the intensity ratio of at least two of the four ions (m/z253, 275, 289 and 291) shall not exceed the same ion intensity ratio of the standard solution by ±20%. 5.6.3 Determination
Measure 1μL of the sample solution for injection. The retention time of 3-MCPD and d5-3-MCPD is about 16min. Record the peak areas of 3-MCPD and d5-3-MCPD. Calculate the peak area ratio of 3-MCPD (m/z253) and d5-3-MCPD (m/z257), and draw a standard curve with the injection amount (ng) of each series of standard solutions and the corresponding peak area ratio of 3-MCPD (m/z235) and d5-3-MCPD (m/z257). 5.7 Result calculation
Calculate the content of 3-chloro-1,2-propanediol in the sample by the internal standard method. See the following formula: X=Axf
Wherein,
X——3-nitrogen-1,2-propanediol content in the sample, in micrograms per kilogram (or micrograms per liter) [ug/kg (or ug/L)];A——3-nitrogen-1.2-propanediol mass corresponding to the peak area ratio of the sample chromatographic peak to the internal standard chromatographic peak, in nanogram (ng);——dilution factor of the sample solution
mThe sample volume, in grams (or milliliters) [g (or mL)]. The calculation result is expressed to three significant figures. 6 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 20% of the arithmetic mean. 517
GB/T5009.191—2003
7 Others
d5-3-MCPD.m/z257
14.39014.65514.994
3 -MCPD,m/z253
14.14314.38114.618
TTTTTTTTTT
FTTTTT
15.66216.06316.336| |tt||TTTTTTTTTTTT
Figure 13-Chloro-1,2-propanediol and its substituted isotopes Full scan total ion chromatogram 100
119147
3-MCPD
289327
341363413429453489498
ehamee
d5-3-MCPD
197,201
397413431456 464 496
t /hm/h:fjnnmhn/hmmrh/hgompap43m/z
Figure 23-Chloro-1,2-propanediol and its substituted isotope mass spectrum 100
d5-3MCPD,m/z257，294.296,45616.175
3-MCPD,m/z253，275，289291,453d5-3-MCPD,m/z257
3-MCPD,m/z253| |tt||Figure 3 Selective ion total ion chromatogram of 3-chloro-1,2-propanediol and its substituted isotopes 518
275.00289.00
3-MCPD
GB/T5009.191-—2003
mywym/2
d5-3-MCPD
mmmmrdm/z
Figure 4 Selected ion mass spectrum of 3-chloro-1,2-propanediol and its substituted isotopes 5192 Sample extraction
Divide a bag of ExtrelutTM20 column filler into two parts, take one part and add it to the sample solution, mix well, and load the other part of the column filler into the chromatography column (fill the lower end of the chromatography column with glass wool). Load the mixture of the sample and the adsorbent into the chromatography column, and add 1 cm of anhydrous sodium sulfate to the upper layer. After standing for 15 minutes, elute the non-polar components with 80 mL of n-hexane-ether (9+1) and discard. Elute 3-MCPD with 250 mL of ether (flow rate is about 8 mL/min). Add 15 g of anhydrous sodium sulfate to the collected ether, let it stand for 10 minutes and filter. Rotate and evaporate the filtrate at 35°C to about 2 mL, transfer quantitatively to a 5 mL stoppered test tube, and dilute to 4 mL with ether. Add a small amount of anhydrous sodium sulfate to the ether, shake, and let it stand for more than 15 minutes. 5.3 Derivatization
Pipette 1 mL of the sample solution, cover it in a 5 mL stoppered test tube, and blow it to near dryness with a nitrogen evaporator at room temperature, immediately add 1 mL of 2,2,4-trimethylpentane: add 0.05 mL of heptafluorobutyryl imidazole with a gas-tight needle, and immediately seal it. After vortex mixing, keep it at 70℃ for 20 minutes. After taking it out, put it at room temperature, add 3 mL of saturated sodium chloride solution, vortex mix for 30 seconds, and separate the two phases. Take the organic phase and add about 0.3 g of anhydrous sodium sulfate to dry. Transfer the solution to a sample bottle for automatic injection for GC-MS determination. 5.4 Preparation of blank sample
Weigh 10 mL of saturated sodium chloride solution (5 mol/L), place it in a 100 mL beaker, add 50 μl of d5-3-MCPD internal standard solution (10 mg/L), and ultrasonicate for 15 minutes. The following steps are the same as the sample extraction and biochemical methods (5.2 and 5.3). 5.5 Preparation of standard series solutions
Pipette 0.1mL of each standard series solution, add 10μL of d5-3-MCPD internal standard solution (10mg/L), add 0.9mL of 2,2,4-trimethylpentane 516
GB/T5009.191—2003
, add 0.05mL of heptafluorobutyrylimidazole with a gas-tight needle, and immediately seal. The following steps are the same as the derivatization method of the sample (5.2 and 5.3).
5.6 Determination
5.6.1 Chromatographic conditions
Chromatographic column: DB-5ms column, 30mX0.25mmX0.25μm. Inlet temperature: 230℃.
Transmission line temperature: 250℃.
Program temperature: 50℃ for 1min, then increase to 90℃ at 2℃/min, then increase to 250℃ at 40℃/min, and maintain for 5min.
Carrier gas: red gas, column head pressure is 6psi.
Splitless injection, injection volume 1μL.
5.6.2 Mass spectrometry parameters
Ionization mode: electron impact source (EI), energy is 70eV. Ion source temperature is 200℃.
Analyzer (electron multiplier) voltage is 450V. Solvent delay is 12min, and mass spectrometry acquisition time is 12min~18min. Scanning method: Selected ion scanning (SIM) is used for acquisition. The characteristic ions of 3-MCPD are m/z253, 275, 289, 291 and 453, and the characteristic ions of d5-3-MCPD are m/z257, 294, 296 and 456. Select different ion channels, use m/z253 as the quantitative ion of 3-MCPD, m/z257 as the quantitative ion of d5-3-MCPD, and use m/z253, 275, 289, 291 and 453 as the qualitative identification ions of 3-MCPD. Investigate the intensity ratio of each fragment ion to the m/z453 ion. The requirement is that the intensity ratio of at least two of the four ions (m/z253, 275, 289 and 291) shall not exceed the same ion intensity ratio of the standard solution by ±20%. 5.6.3 Determination
Measure 1μL of the sample solution for injection. The retention time of 3-MCPD and d5-3-MCPD is about 16min. Record the peak areas of 3-MCPD and d5-3-MCPD. Calculate the peak area ratio of 3-MCPD (m/z253) and d5-3-MCPD (m/z257), and draw a standard curve with the injection amount (ng) of each series of standard solutions and the corresponding peak area ratio of 3-MCPD (m/z235) and d5-3-MCPD (m/z257). 5.7 Result calculation
Calculate the content of 3-chloro-1,2-propanediol in the sample by the internal standard method. See the following formula: X=Axf
Wherein,
X——3-nitrogen-1,2-propanediol content in the sample, in micrograms per kilogram (or micrograms per liter) [ug/kg (or ug/L)];A——3-nitrogen-1.2-propanediol mass corresponding to the peak area ratio of the sample chromatographic peak to the internal standard chromatographic peak, in nanogram (ng);——dilution factor of the sample solution
mThe sample volume, in grams (or milliliters) [g (or mL)]. The calculation result is expressed to three significant figures. 6 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 20% of the arithmetic mean. 517
GB/T5009.191—2003
7 Others
d5-3-MCPD.m/z257
14.39014.65514.994
3 -MCPD,m/z253
14.14314.38114.618
TTTTTTTTTT
FTTTTT
15.66216.06316.336| |tt||TTTTTTTTTTTT
Figure 13-Chloro-1,2-propanediol and its substituted isotopes Full scan total ion chromatogram 100
119147
3-MCPD
289327
341363413429453489498
ehamee
d5-3-MCPD
197,201
397413431456 464 496
t /hm/h:fjnnmhn/hmmrh/hgompap43m/z
Figure 23-Chloro-1,2-propanediol and its substituted isotope mass spectrum 100
d5-3MCPD,m/z257，294.296,45616.175
3-MCPD,m/z253，275，289291,453d5-3-MCPD,m/z257
3-MCPD,m/z253| |tt||Figure 3 Selective ion total ion chromatogram of 3-chloro-1,2-propanediol and its substituted isotopes 518
275.00289.00
3-MCPD
GB/T5009.191-—2003
mywym/2
d5-3-MCPD
mmmmrdm/z
Figure 4 Selected ion mass spectrum of 3-chloro-1,2-propanediol and its substituted isotopes 5192 and 5.3).
5.6 Determination
5.6.1 Chromatographic conditions
Chromatographic column: DB-5ms column, 30mX0.25mmX0.25μm. Inlet temperature: 230℃.
Transmission line temperature: 250℃.
Program temperature: maintain at 50℃ for 1 min, increase to 90℃ at a rate of 2℃/min, then increase to 250℃ at a rate of 40℃/min and maintain for 5 min.
Carrier gas: red gas, column head pressure is 6 psi.
Splitless injection, injection volume 1μL.
5.6.2 Mass spectrometry parameters
Ionization mode: electron impact source (EI), energy is 70eV. The ion source temperature was 200 °C.
The analyzer (electron multiplier) voltage is 450V. The solvent delay was 12 min, and the mass spectrometry acquisition time was 12 min to 18 min. Scanning mode: Selected ion scanning (SIM) was used for acquisition. The characteristic ions of 3-MCPD were m/z 253, 275, 289, 291 and 453, and the characteristic ions of d5-3-MCPD were m/z 257, 294, 296 and 456. Different ion channels were selected, with m/z253 as the quantitative ion for 3-MCPD, m/z257 as the quantitative ion for d5-3-MCPD, and m/z253, 275, 289, 291 and 453 as the qualitative identification ions for 3-MCPD. The intensity ratio of each fragment ion to the m/z453 ion was examined, with the requirement that the intensity ratio of at least two of the four ions (m/z253, 275, 289 and 291) should not exceed ±20% of the intensity ratio of the same ions in the standard solution. 5.6.3 Determination
Measure 1 μL of the sample solution and inject it. The retention time of 3-MCPD and d5-3-MCPD was about 16 min. The peak areas of 3-MCPD and d5-3-MCPD were recorded. The peak area ratio of 3-MCPD (m/z 253) and d5-3-MCPD (m/z 257) was calculated, and the standard curve was drawn with the injection amount (ng) of each series of standard solutions and the corresponding peak area ratio of 3-MCPD (m/z 235) and d5-3-MCPD (m/z 257). 5.7 Calculation of results
Calculate the content of 3-chloro-1,2-propanediol in the sample using the internal standard method. See the following formula: X=Axf
wherein,
X——3-nitrogen-1,2-propanediol content in the sample, in micrograms per kilogram (or micrograms per liter) [ug/kg (or ug/L)]; A——the mass of 3-nitrogen-1.2-propanediol corresponding to the peak area ratio of the sample chromatographic peak to the internal standard chromatographic peak, in nanogram (ng);——dilution multiple of the sample solution
mthe sampling volume of the sample, in grams (or milliliters) [g (or mL)]. The calculation results are expressed to three significant figures. 6 Precision
The absolute difference between two independent measurement results obtained under repeatability conditions shall not exceed 20% of the arithmetic mean. 517
GB/T5009.191—2003
7 Others
d5-3-MCPD.m/z257
14.39014.65514.994
3 -MCPD,m/z253
14.14314.38114.618
TTTTTTTTTT
FTTTTT
15.66216.06316.336| |tt||TTTTTTTTTTTT
Figure 13-Chloro-1,2-propanediol and its substituted isotopes Full scan total ion chromatogram 100
119147
3-MCPD
289327
341363413429453489498
ehamee
d5-3-MCPD
197,201
397413431456 464 496
t /hm/h:fjnnmhn/hmmrh/hgompap43m/z
Figure 23-Chloro-1,2-propanediol and its substituted isotope mass spectrum 100
d5-3MCPD,m/z257，294.296,45616.175
3-MCPD,m/z253，275，289291,453d5-3-MCPD,m/z257
3-MCPD,m/z253| |tt||Figure 3 Selective ion total ion chromatogram of 3-chloro-1,2-propanediol and its substituted isotopes 518
275.00289.00
3-MCPD
GB/T5009.191-—2003
mywym/2
d5-3-MCPD
mmmmrdm/z
Figure 4 Selected ion mass spectrum of 3-chloro-1,2-propanediol and its substituted isotopes 5192 and 5.3).
5.6 Determination
5.6.1 Chromatographic conditions
Chromatographic column: DB-5ms column, 30mX0.25mmX0.25μm. Inlet temperature: 230℃.
Transfer line temperature: 250℃.
Program temperature: 50℃ for 1min, increase to 90℃ at a rate of 2℃/min, then increase to 250℃ at a rate of 40℃/min, and maintain for 5min.
Carrier gas: red gas, column head pressure is 6psi.
Splitless injection, injection volume 1μL.
5.6.2 Mass spectrometry parameters
Ionization mode: electron impact source (EI), energy is 70eV. Ion source temperature is 200℃.
Analyzer (electron multiplier) voltage is 450V. The solvent delay is 12 minutes, and the mass spectrometry acquisition time is 12 minutes to 18 minutes. Scanning method: Selected ion scanning (SIM) acquisition is used. The characteristic ions of 3-MCPD are m/z253, 275, 289, 291 and 453, and the characteristic ions of d5-3-MCPD are m/z257, 294, 296 and 456. Different ion channels are selected, with m/z253 as the quantitative ion of 3-MCPD, m/z257 as the quantitative ion of d5-3-MCPD, and m/z253, 275, 289, 291 and 453 as the qualitative identification ions of 3-MCPD. The intensity ratio of each fragment ion to the m/z453 ion is examined. The requirement is that the intensity ratio of at least two of the four ions (m/z253, 275, 289 and 291) shall not exceed the same ion intensity ratio of the standard solution by ±20%. 5.6.3 Determination
Take 1μL of the sample solution for injection. The retention time of 3-MCPD and d5-3-MCPD is about 16min. Record the peak areas of 3-MCPD and d5-3-MCPD. Calculate the peak area ratio of 3-MCPD (m/z253) and d5-3-MCPD (m/z257), and draw a standard curve with the injection amount (ng) of each series of standard solutions and the corresponding peak area ratio of 3-MCPD (m/z235) and d5-3-MCPD (m/z257). 5.7 Result calculation
Calculate the content of 3-chloro-1,2-propanediol in the sample by the internal standard method. See the following formula: X=Axf
Wherein,
X——3-nitrogen-1,2-propanediol content in the sample, in micrograms per kilogram (or micrograms per liter) [ug/kg (or ug/L)];A——3-nitrogen-1.2-propanediol mass corresponding to the peak area ratio of the sample chromatographic peak to the internal standard chromatographic peak, in nanogram (ng);——dilution factor of the sample solution
mThe sample volume, in grams (or milliliters) [g (or mL)]. The calculation result is expressed to three significant figures. 6 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 20% of the arithmetic mean. 517
GB/T5009.191—2003
7 Others
d5-3-MCPD.m/z257
14.39014.65514.994
3 -MCPD,m/z253
14.14314.38114.618
TTTTTTTTTT
FTTTTT
15.66216.06316.336| |tt||TTTTTTTTTTTT
Figure 13-Chloro-1,2-propanediol and its substituted isotopes Full scan total ion chromatogram 100
119147
3-MCPD
289327
341363413429453489498
ehamee
d5-3-MCPD
197,201
397413431456 464 496
t /hm/h:fjnnmhn/hmmrh/hgompap43m/z
Figure 23-Chloro-1,2-propanediol and its substituted isotope mass spectrum 100
d5-3MCPD,m/z257，294.296,45616.175
3-MCPD,m/z253，275，289291,453d5-3-MCPD,m/z257
3-MCPD,m/z253| |tt||Figure 3 Selective ion total ion chromatogram of 3-chloro-1,2-propanediol and its substituted isotopes 518
275.00289.00
3-MCPD
GB/T5009.191-—2003
mywym/2
d5-3-MCPD
mmmmrdm/z
Figure 4 Selected ion mass spectrum of 3-chloro-1,2-propanediol and its substituted isotopes 519Full scan total ion chromatogram of 2-propylene glycol and its substituted isotopes 100
119147
3-MCPD
289327
341363413429453489498
ehamee
d5-3-MCPD
197,201
397413431456 464 496
t /hm/h:fjnnmhn/hmmrh/hgompap43m/z
Figure 23-Chloro-1,2-propanediol and its substituted isotope mass spectrum 100
d5-3MCPD,m/z257，294.296,45616.175
3-MCPD,m/z253，275，289291,453d5-3-MCPD,m/z257
3-MCPD,m/z253| |tt||Figure 3 Selective ion total ion chromatogram of 3-chloro-1,2-propanediol and its substituted isotopes 518
275.00289.00
3-MCPD
GB/T5009.191-—2003
mywym/2
d5-3-MCPD
mmmmrdm/z
Figure 4 Selected ion mass spectrum of 3-chloro-1,2-propanediol and its substituted isotopes 519Full scan total ion chromatogram of 2-propylene glycol and its substituted isotopes 100
119147
3-MCPD
289327
341363413429453489498
ehamee
d5-3-MCPD
197,201
397413431456 464 496
t /hm/h:fjnnmhn/hmmrh/hgompap43m/z
Figure 23-Chloro-1,2-propanediol and its substituted isotope mass spectrum 100
d5-3MCPD,m/z257，294.296,45616.175
3-MCPD,m/z253，275，289291,453d5-3-MCPD,m/z257
3-MCPD,m/z253| |tt||Figure 3 Selective ion total ion chromatogram of 3-chloro-1,2-propanediol and its substituted isotopes 518
275.00289.00
3-MCPD
GB/T5009.191-—2003
mywym/2
d5-3-MCPD
mmmmrdm/z
Figure 4 Selected ion mass spectrum of 3-chloro-1,2-propanediol and its substituted isotopes 519
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