GB 23200.58-2016Food safety national standard -- Determination of residual residues of chlorhexonium chloride in food by liquid chromatography-mass spectrometry / mass spectrometry (English PDF)

4.1 Reagents

4.1.1 Acetonitrile (CH3CN).

4.1.2 Ammonium acetate (CH3COONH4).

4.1.3 Acetic acid (CH3COOH).

4.1.4 Formic acid (HCOOH).

4.1.5 anhydrous magnesium sulfate (MgSO4). analytical grade.

4.1.6 anhydrous sodium acetate (CH3COONa). analytical grade.

4.2 Solution preparation

4.2.1 Acetic acid-acetonitrile solution (1 99, V/V). Take 10 mL of acetic acid, add 990 mL of acetonitrile and mix well.

4.2.2 5 mm ol/L ammonium acetate solution (containing 0.1% formic acid). accurately weighed 77.0 mg ammonium acetate in.200 mL volumetric flask, first with A small amount of water dissolved after adding.200 µL formic acid, and then the water volume to the scale, mixing, is now with the distribution.

4.3 Standards

4.3.1 clausansulamines (cloransulam-methyl). CAS No. 147150-35-4, molecular formula C15H13FN5O5SCl, points Molecular weight 429.81, purity >= 99%.

4.4 Standard solution preparation

4.4.1 standard solution of chlorhexonium bromide standard solution. accurately weighed the appropriate amount of chlorhexidine sulfa standard (accurate to 0.1 mg), with acetonitrile dissolved Solution, prepared into 1000µg/mL standard stock solution, stored at -18 °C.

4.4.2 Chlorobenzenesulfonium standard working solution. diluted with acetonitrile as required 1µg/mL standard working solution, stored at -18 °C.

4.4.3 Substrate blank solution. The solution obtained by treating the negative samples of different substrates according to "7 Analysis Procedure".

4.4.4 matrix standard working fluid. according to the needs of the experiment to absorb the appropriate amount of standard solution of chlorhexonium bromide solution, diluted with a matrix blank solution when the concentration of the standard working fluid, is now available.

4.5 Materials

4.5.1 Graphitized Carbon Black Adsorbent. 120 µm to 400 µm.

4.5.2 N-propyl ethylenediamine (PSA) adsorbent. 40 µm to 60 µm.

4.5.3 Octadecylsilane (ODS) Bonded Adsorbent (C18). 40 µm to 60 µm.

4.5.4 Microporous membrane. 0.2µm, organic phase type.

6.1 Corn, rice, soybeans, chestnuts, walnuts, tea leaves

500 g of the sample was taken and pulverized with a pulverizer. Mix, are divided into two as a sample, into the clean Sheng Sheng bag, dense Closed, stored at 0 ~ 4 °C.

6.2 Cabbage, tomato, pepper, spinach, onion, orange, strawberry, mango, cherry, mushroom

After picking the sample 1000 g, (without water washing), the sample was processed into a slurry by a mashing machine. Mix, are divided into Two as a sample, into the clean Sheng Sheng bag, sealed. The sample was stored at -18 ° C or lower.

6.3 Chicken liver, liver

After picking 500 g of the sample, it was chopped and the sample was processed into a slurry by a mashing machine, and the mixture was divided into two portions.

Kind, into the clean Sheng Sheng bag, sealed. The sample was stored at -18 ° C or lower.

6.4 Milk

To replace the sample of about 500g, mix, are divided into two as a sample, divided into a clean vial, sealed. Will sample on 0 ~ 4 °C under the conditions of preservation.

Note. The above sample sampling site according to GB 2763 Appendix A implementation.

Note. During the operation of the sample preparation, the sample should be prevented from being contaminated or the change in the residual content of the chlorhexonium chloride.

7.1 Extraction

7.1.1 Corn, rice, soybeans, chestnuts, walnuts, tea leaves

Weigh 5 g (accurate to 0.01 g) sample in 50 mL polytetrafluoroethylene centrifuge tube, add appropriate amount of water (about 5 ~ 8mL, depending on the specific sample) Soak for 0.5 h. Add 1% acetic acid acetonitrile to the total volume of acetonitrile and water 20 mL to 10000 r/min homogenization 0.5min, shake, at 40 °C Under ultrasonic extraction for 30 min, centrifuged at 8500 r/min for 10 min. Take the supernatant 1mL, plus PSA and C18 50mg, the pigment interference large sample such as tea, etc., by adding 5mg graphitized carbon black, shaking vigorously 1min, 8000 r/min centrifugal 10min, take the supernatant with 0.2µm filter and then used for liquid chromatography-mass spectrometry/mass spectrometry.

7.1.2 cabbage, tomato, pepper, spinach, onion, orange, strawberry, mango, cherry, mushrooms, chicken liver, liver Weigh 5 g (accurate to 0.01 g) sample in a 50 mL polytetrafluoroethylene centrifuge tube. Accurately add 1% acetic acid acetonitrile to 20 mL, the next steps are the same as 7.1.1.

7.1.3 Milk

Weigh 5 g (accurate to 0.01 g) sample in a 50 mL polytetrafluoroethylene centrifuge tube. Accurately add 1% acetic acid acetonitrile to 20 mL, the next steps are the same as 7.1.1.

7.2 Determination

7.2.1 Liquid Chromatographic Reference Conditions

A) liquid chromatography column. ACQUITY UPLC BEH C18, 50 mm × 2.1 mm (i .d.), Particle size 1.7 µm, or performance equivalent.

B) Column temperature. 35 ° C.

C) mobile phase gradient. see Table 1.

Table 1 Mobile phase elution gradient table

time

(Min)

Flow rate

(ML/min)

(5 mmol/L ammonium acetate solution (containing 0.1% formic acid) (4.8) % B (Acetonitrile) Curve class

1 Initial 0.25 90 10 2 0.30 0.25 10 90 6 3 0.40 0.25 10 90 1 4 1.4 0.25 90 10 6 5 1.5 0.25 90 10 1 D) Injection volume. 5.0 µL.

E) Sample chamber temperature. 10 ° C.

7.2.2 Mass spectrometry reference conditions

A) Scan mode. ESI.

B) Detection method. MRM;

C) Mass Spectral Reference Conditions. See Appendix A.

7.2.3 Drawing of standard curves

Before the sample analysis, dilute the mixed standard intermediate solution with a blank sample extraction solution as necessary and mix with the appropriate concentration of the matrix Standard working fluid, for the standard working curve, and should be used with the current distribution.

A blank space of 5 g was fixed to 20 mL with acetonitrile and the matrix blank solution was prepared by pre-treatment step (7.1). The standard intermediate Solution dilution to 2.0,5.0,10.0,12.0,15.0,20.0 ng/mL, but the origin to do the standard working curve.

7.3 Quantitative determination

In this method, liquid chromatography-tandem mass spectrometry was quantitatively determined by external standard calibration curve method. To reduce the effect of matrix on quantitative determination, quantitative the standard curve should be drawn using the standard solution of the matrix mixed standard working solution, and the response value of the pesticide in the tested sample should be Within the linear range. According to the sample solution of the content of chlorhexidine octaroma, selected similar concentrations of standard working solution. Under the above instrument conditions, the retention time of the chlorhexidine herb is about 1.17 min, and the multi-reactive ion monitoring chart is shown in Figure B.1 in Appendix B.

7.4 Qualitative determination

The standard solution and sample solution are checked according to the above conditions, if the sample solution and the standard solution in the same retention time peak Now, it is confirmed by mass spectrometry, after deducting the background of the sample spectrum, the selected ions all appear, while the selected ion the abundance of ions is consistent with the relative abundance of the ions associated with the standard, and the relative ion abundance deviation does not exceed the specified range of Table 2, in the presence of chlorhexonium bromide. The total ion chromatogram and mass spectrum of the chlorhexidine herb standard are given in Appendix B.

Table 2 Qualitative determination of relative ion abundance maximum allowable deviation

7.5 Blank test

In addition to no sample, according to the above steps.

10.1 Quantitation limits

The quantification limit of this method to chlorhexonium bromide is 0.010 mg/kg.

10.2 Recovery rate

The range of addition and recovery of this method is given in Appendix C.

Relative abundance (base) 50% 20% to 50% 10% to 20% <=10% Allowable relative deviation ± 20% ± 25% ± 30% ± 50% Appendix A (Informative) Reference conditions for the spectrum of chlorhexidine Chlorobenzenesulfonic acid Mass Spectrometry Reference conditions.

A) Ionization mode. ESI;

B) Detection method. MRM;

C) Capillary voltage. 3.00 kV;

D) nitrogen blowing flow. 800 L/h;

E) Taper hole air flow. 148 L/h;

F) Solvent gas temperature. 350 ° C;

G) Amplifier voltage. 650 V;

H) ion source temperature. 105 ° C;

I) monitoring of ions, collision energy and cone hole voltage (see Table A.1).

Table A.1 Multi-reactive ion monitoring and analysis parameters of chlorhexidine herb

Component

Compound

Monitor ion pairs

Channel Reaction

Dwell time

Dwell (secs)

Collision energy

Collision Energy (V) Cone hole voltage Cone (V) Chlorobenzenesulfonium chloride * 430/153 0.1 40.0 30.0 430/370 0.1 20.0 30.0 430/398 0.1 10.0 30.0 * For quantitative ion pairs Note. The above listed parameters were completed at the Waters AcquityTM UPLC-Quattro Premier mass spectrometer, listing the test instrument model only to provide Test, does not involve commercial purposes, to encourage standard users to try to use different manufacturers or models of equipment.

Appendix B

(Informative)

Chlorosalicylamine standard solution

Figure B.1 Multi-reaction monitoring (MRM) of LC-MS/MS for standard solution of chlorhexonium bromide

Appendix C

(Informative)

Sample concentration and recovery of the experimental data

Table C.1 Concentration and Recovery Rate of Chlorobenzenesulfonium in Different Substrate Samples (%) (n = 8)

Sample concentration (mg/kg) Recovery range (%) corn 0.010 90.4 to 103.2 0.020 93.8 ~ 100.6 0.040 97.2 ~ 104.2 Rice 0.010 73.6 ~ 104.0 0.020 86.8 ~ 92.6 0.040 84.2 to 89.4 Soybeans 0.010 80.0 to 102.4 0.020 87.8 ~ 105.8 0.030 94.0 to 104.4 0.040 87.0 to 102.2 0.060 99.5 to 110.4 0.120 111.9 to 118.9 chestnut 0.010 92.2 to 98.9 0.020 84.6 to 89.4 0.040 82.0 to 85.8 walnut 0.010 110.7 to 117 0.020 106.9 to 116.7 0.040 85.1 to 99.3 Cabbage 0.010 95.6 ~ 101.6 0.020 94.8 ~ 98.6 0.040 97.5 to 110.5 tomato 0.010 96.8 to 107.2 0.020 98.2 ~ 105 0.040 95.8 ~ 101.6 chili 0.010 82.8 to 95.6 0.020 90.2 to 98.8 0.040 91.5 to 98.6 Strawberry 0.010 89.2 ~ 99.6 0.020 105.6 ~ 115.8 0.040 85.9 ~ 102.5 Mango 0.010 102.4 ~ 117.2 0.020 85 to 96.6 0.040 73.5 ~ 94.2 Cherry 0.010 77.6 ~ 105.2 0.020 107.4 ~ 116.6 0.040 95.5 to 112.2 Chicken liver 0.010 74.5 to 82.9 0.020 84.5 to 99.5 0.040 79.2 ~ 107.2 milk 0.010 90.4 to 100.4 0.020 99.2 ~ 106.8 0.040 103.2 to 110.7 tea 0.010 92.4 ~ 102 0.020 87 ~ 100.2 0.040 91.8 to 99.4 onion 0.010 83.2 ~ 98.8 0.020 90 to 101.4 0.040 86.9 ~ 111.0 Mushrooms 0.010 89.2 ~ 99.6 0.020 94.6 ~ 99.6 0.040 77.5 to 84.8 spinach 0.010 96.8 to 105.2 0.020 96.6 to 100.0 0.040 100.6 ~ 105.7 Liver 0.010 74.4 to 100.8 0.020 98 ~ 100.4 0.040 96.1 to 99.8 orange 0.010 87.6 ~ 98 0.020 100 to 106 0.040 110.7 to 116.1 Appendix D (Normative appendix) Laboratory repeatability requirements

Table D.1 Laboratory repeatability requirements

Measured component content Mg/kg Precision <=0.001 36 > 0.01 > 1 14 Appendix E (Normative appendix) Inter-laboratory reproducibility requirements

Table E.1 Inter-laboratory reproducibility requirements

Measured component content Mg/kg Precision <=0.001 54 > 0.01 > 1 19