SN/T 5112-2019Determination of propylene glycol in edibe animals and feeds for import and export -- GC Method and GC-MS method (English PDF)

5.3 Sample crusher

5.4 Nitrogen blowing concentration station.

5.5 Vortex the mixer.

5.6 Ultrasonic water bath.

5.7 High-speed centrifuge. Rotation speed >=1000r/min.

5.8 Scale test tube. 5mL.

5.9 Colorimetric tube with stopper. 10mL.

5.10 Centrifuge tube with stopper. 15mL.

6.1 Sample treatment

6.1.1 Serum matrix

Weigh 2g (accurate to 0.01g) sample into a 10mL colorimetric tube, slowly add acetonitrile to the nearest scale under vortex, and cover with ultrasonic extraction 5min, take it out to room temperature, make up to volume with acetonitrile, and mix well. Transfer this extract to a 15mL stoppered centrifuge tube at 10,000r/min.

Centrifuge for 3 min. Accurately transfer 5.0mL of the supernatant to a 5mL graduated test tube, and concentrate it to about 0.5mL at 50 ° C in a nitrogen blower.

Reconstitute with ethanol, make up to volume, mix well, pass 0.45 µm organic phase filter membrane, and bottle until ready for use.

6.1.2 Urine matrix

Weigh 2g (accurate to 0.01g) sample into a 10mL colorimetric tube, slowly add acetonitrile to the nearest scale under vortex, and cover with ultrasonic extraction 5min, take it out to room temperature, make up to volume with acetonitrile, and mix well. Add about 1.5g of anhydrous magnesium sulfate to the colorimetric tube, cover with a vortex, and the extract was transferred to a 15 mL stoppered centrifuge tube, centrifuged at 1,000 r/min for 3 min, and the supernatant was passed through an organic phase filter membrane of 0.45 µm, and bottled for use on the machine.

6.1.3 Milk base

Weigh 2g (accurate to 0.01g) sample into a 10mL colorimetric tube, slowly add acetonitrile to the nearest scale under vortex, and cover with ultrasonic extraction 5min, take it out to room temperature, make up to volume with acetonitrile, and mix well. Transfer 1.0 mL of the supernatant to the purification tube (4.9), cover with a vortex, and Centrifuge at 10,000 r/min for 3 min, take the supernatant and pass it through an organic phase filter membrane of 0.45 µm, and bottle it for loading onto the machine.

6.1.4 Feed substrate

The sample was pulverized with a pulverizer, 1g (accurate to 0.0001g) of feed was weighed into a 15mL centrifuge tube with a stopper, and 10.0mL of B was accurately added.

Nitrile, cap and shake to mix well, extract 15 min by ultrasonic, take it out to room temperature, and centrifuge at 10,000 r/min for 3 min. Pipette supernatant in a 1000mL to 10mL colorimetric tube, make up to volume with ethanol and mix well. Take the diluted solution through a 0.45µm organic phase filter and bottle it for use on the machine.

SN/T 51212-2019 ????? ????, ????,?

6.2 Sample determination

6.2.1 Instrument reference conditions

6.2.1.1 Chromatographic column. bonded/crosslinked polyethylene glycol stationary phase quartz capillary column, 30m × 0.25mm × 0.25µm, or equivalent.

6.2.1.2 Carrier gas. high-purity nitrogen; constant flow mode, flow rate. 1.0mL/min.

6.2.1.3 Heating procedure. the initial temperature of the column is 50 ° C, and it is maintained for 1 min; the temperature is increased to 15 ° C/min to 170 ° C, and is maintained for 3 min, the temperature was raised from 20 ° C/min to 230 ° C and kept at 3min.

6.2.1.4 The inlet temperature is 230 ° C.

6.2.1.5 Detector temperature. 240 ° C.

6.2.1.6 Makeup gas flow is 30mL/min.

6.2.1.7 The hydrogen flow rate is 30 mL/min.

6.2.1.8 The air flow rate is 300 mL/min.

6.2.1.9 Injection volume. 1.0 µL. 6.2.1.10 Injection method. split injection, split ratio is 5. 1.

6.2.2 Preparation of standard curve

Inject the standard series of working solution into the gas chromatograph, and determine the chromatographic peak area of the corresponding propylene glycol.

The concentration is plotted on the abscissa and the peak area of the chromatographic peak is plotted on the ordinate to draw a standard curve.

6.2.3 Determination of sample solution

The sample solution was injected into the gas chromatograph to obtain the corresponding chromatographic peak area of 1,2-propanediol. The test solution was obtained according to the standard curve.

The mass concentration of 1,2-propanediol and 1,3-propanediol. See Figure A for the standard gas chromatogram of propylene glycol. 1.

8.1 Low limit of determination

The lower limit of determination of 1,2-propanediol and 1,3-propanediol in serum, urine and milk of food animals by this method is 0.01g/kg. this Methods The lower limit of determination of 1,2-propanediol and 1,3-propanediol in feed was 0.20 g/kg.

SN/T 51212-2019 ????? ????, ????,?

8.2 Recovery rate and precision

See Appendix B for recovery data.

Gas chromatography-mass spectrometry

12.1 Sample treatment

12.1.1 Matrix for liquid samples such as serum, urine and milk

Weigh 2g (accurate to 0.0001g) sample into a 10mL colorimetric tube, slowly add acetonitrile to the near scale under vortex, cover with ultrasonic vibration to extract Take 5min, take out to room temperature, make up to volume with acetonitrile and mix well. Transfer this extract to a 15mL centrifuge tube with a stopper at 10,000r/min.

Centrifuge for 3 min, accurately transfer 5.0 mL of supernatant to a 5 mL graduated test tube, and concentrate at 50 ° C with nitrogen blowing to about 0.5 mL.

Ethanol was reconstituted, the volume was adjusted, and the mixture was homogenized. After passing through the 0.45 µm organic phase filter membrane, it was bottled and put on the machine.

12.1.2 Feed and other solid sample matrix

The sample was pulverized with a pulverizer, 1g (accurate to 0.0001g) of feed was weighed into a 15mL centrifuge tube, and 10.0mL of acetonitrile was accurately added.

Cover well, extract 15 min by ultrasonic vibration, take it out to room temperature, and centrifuge at 10,000 r/min for 3 min. Accurately draw supernatant 1.0mL in a 10mL colorimetric tube, dilute with ethanol and mix. Take the diluted solution through the 0.45 µm organic phase filter membrane and bottle it for use on the machine.

12.2 Determination of samples

12.2.1 Instrument reference conditions

12.2.2.1.1 Chromatographic column. Bonded/crosslinked polyethylene glycol stationary phase quartz capillary column, 30m × 0.25mm (inner diameter) × 0.25µm (film thickness), or equivalent.

12.2.2.1.2 The carrier gas is high-purity helium, in constant current mode, and the flow rate is 1.0 mL/min.

12.2.2.1.3 Temperature rising procedure. the initial temperature of the column is 50 ° C and maintained for 1 min;

The temperature rise rate from 20 ° C/min to 230 ° C was maintained for 3 min.

12.2.2.1.4 Inlet temperature. 230 ° C.

12.2.2.1.5 Injection volume. 1.0 µL.

12.2.2.1.6 Injection method. split injection, split ratio is 20. 1.

12.2.2.1.7 Ion source temperature. 230 ° C.

12.2.2.1.8 Electron impact ionization source (EI). 70 eV.

12.2.2.1.9 Interface (transmission line) temperature. 240 ° C.

12.2.2.10 Select ion monitoring mode (SIM). 1.2-propanediol Quantitative ion. m/z45, Qualifier ion. m/m31,61;

Quantitative ion. m/z58, Qualitative ion. m/z31,28.

12.2.2.11 Solvent delay time. 6 min.

12.2.2 Qualitative determination

If the sample retention time is consistent with the standard solution (± 0.5%) and the background spectrum is subtracted from the sample mass spectrum, the selected ion If all the ions are present, and the selected ion abundance ratio is consistent with the ion abundance ratio of the standard sample, it can be judged that the measured Thing. When using gas chromatography-mass spectrometry, the maximum allowable error of relative ion abundance is shown in Table 1.

Table 1 Maximum allowable deviation of relative ion abundance during qualitative analysis

Relative ion abundance > 50% > 20% to 50% > 10% to 20% <= 10% Allowable relative deviation ± 10% ± 15% ± 20% ± 50% SN/T 51212-2019 ????? ????, ????,?

12.2.3 Quantitative determination

According to the content of the test substance in the sample, select a standard working solution with a suitable response value for chromatographic analysis. The standard curve working solution should reach There are as few as 5 concentration levels, excluding zero. The response values of the two compounds in the standard working solution and the test solution should be within the linear response range of the instrument.

Within. Select ion scanning chromatogram of propylene glycol is shown in Figure C. 1.

14.1 Low limit of determination

The lower limit of determination of 1,2-propanediol and 1,3-propanediol in serum, urine and milk of food animals by this method is 0.01g/kg. this Methods The lower limit of determination of 1,2-propanediol and 1,3-propanediol in feed was 0.20 g/kg.

14.2 Recovery and precision

See Appendix D for recovery data.

SN/T 51212-2019 ????? ????, ????,?

Appendix A

(Informative appendix) Propylene glycol gas chromatogram SN/T 51212-2019 ????? ????, ????,?

Appendix B

(Informative appendix) GC recovery B. 1 Experimental data of concentration and recovery of gas chromatography (n = 8) Compound matrix addition level mg/kg Recovery rate relative standard deviation 1,2-propanediol serum 10.0 81.9 to 108.8 9.8 28.0 82.8 to 102.9 8.2 100 91.5 to 101.9 4.1 Urine 10.0 85.5 to 104.7 7.3 20.0 81.5 to 104.0 8.5 100 84.1 to 105.8 8.2 Milk 10.0 83.6 to 97.3 4.8 20.0 83.5 to 97.5 5.4 100 90.4 to 105.2 5.7 feed 1,000 × 103 91.9 ~ 100.8 2.6 2000 × 103 96.5 ~ 103.2 2.3 5.0 × 103 93.2 ~ 103.0 3.6 1,3-propanediol serum 10.0 90.8 to 103.4 3.8 20.0 92.5 to 103.6 3.7 100 91.2 to 107.0 5.6 Urine 10.0 88.4 to 104.8 5.5 20.0 80.7 to 101.6 7.6 100 84.6 to 107.2 8.2 Milk 10.0 94.8 to 102.8 2.8 20.0 86.5 to 101.1 4.7 100 92.8 ~ 110.8 6.0 feed 1.0 × 103 89.3 ~ 105.2 7.0 2000 × 103 94.7 to 103.7 3.4 5.0 × 103 91.0 ~ 105.0 4.8 SN/T 51212-2019 ????? ????, ????,?

Appendix C

(Informative appendix) Propylene glycol gas chromatography-mass spectrogram and mass spectrum

Figure C. 2 Mass spectrum of 1,2-propanediol standard solution

SN/T 51212-2019 ????? ????, ????,?

Figure C. 3 1,3-propanediol standard solution mass spectrum

SN/T 51212-2019 ????? ????, ????,?

Appendix D

(Informative appendix) Gas chromatography-mass spectrometry added recovery D. 1 Gas chromatography-mass spectrometry addition concentration and recovery experimental data (state = 8) Compound matrix addition level mg/kg Recovery rate relative standard deviation 1,2-propanediol serum 10.0 88.5 to 99.0 3.8 20.0 83.0 ~ 104.0 8.2 100 80.3 to 102.8 9.1 Urine 10.0 89.0 to 102.5 5.4 20.0 91.6 to 105.0 4.9 100 81.0 to 104.2 10.1 Milk 10.0 80.5 to 102.3 8.8 20.0 87.0 to 101.0 5.7 100 80.9 to 105.0 9.2 feed 1,000 × 103 84.2 to 99.7 5.7 2000 × 103 88.7 to 98.9 5.1 5.0 × 103 91.1 ~ 102.0 3.8 1,3-propanediol serum 10.0 89.5 to 109.0 7.9 20.0 86.7 to 104.3 7.4 100 80.1 to 104.5 10.3 Urine 10.0 80.5 to 89.5 3.4 20.0 90.8 to 106.7 5.0 100 83.1 to 100.7 7.6 Milk 10.0 81.5 to 102.0 9.7 20.0 83.6 to 104.0 9.8 100 80.7 to 95.0 6.9 feed 1,000 × 103 84.1 ~ 101.3 7.4 2000 × 103 92.1 ~ 102.1 5.5 5.0 × 103 85.0 ~ 96.10 1.0 SN/T 51212-2019 ????? ????, ????,?