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GB 23200.24-2016Food safety national standard -- Determination of 11 Herbicide Residues in Grain and Soybeans -- Gas Chromatography -- Mass Spectrometry (English PDF)

粮谷和大豆中11种除草剂残留量的测定气相色谱-质谱法

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Issued by

National Health and Family Planning Commission of the People's Republic of China, State Food and Drug Administration

Level / Type

National · Mandatory

Issue date

December 18, 2016

Implementation date

June 18, 2017

Scope

GB 23200.24-2016 is the English-translated version of 粮谷和大豆中11种除草剂残留量的测定气相色谱-质谱法.

GB 23200.24-2016 — This standard specifies the method for the determination of 11 herbicides in grain and soybeans by gas chromatography-mass spectrometry.

This standard applies to rice, corn, wheat and soybean in the acetochlor, pentachlor, alachlor, metolachlor, pendimethalin, grass Amines, fluoroamides, propanamides, oxamine, pyrithione and pendimethacrylide residues in the determination and confirmation, other food can refer to the implementation.

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Document preview — GB 23200.24-2016

National Standard of the People's Republic of China

Classification: G 25
Replacing: SN/T 0712-2010

Issued by: National Health and Family Planning Commission of the People's Republic of China, State Food and Drug Administration

Foreword
1 Scope
2 Normative reference documents
3 Principle
4 Reagents and materials
4.1 Reagents
4.2 Solution preparation
4.3 Standards
4.4 Standard solution preparation
4.5 Materials
5 Instruments and equipment
6 Preparation and storage of samples
6.1 Preparation of the sample
6.2 Sample storage
7 Measurement steps
7.1 Extraction
7.2 Purification
7.3 Determination
7.4 Blank experiment
8 Results are calculated and expressed
9 Precision
10.1 Quantitation limits
10.2 Recovery rate
11 Basic information on herbicide reference materials Table A.1

Foreword

This standard replaces SN/T 0712-2010 "Determination of 11 herbicides in cereals and soybeans for import and export by gas chromatography-mass spectrometry".

Compared with SN/T 0712-2010, the main changes are as follows.

- Standard text format is modified to national standard text format for food safety;

- the name of the "import and export grain" to "grain".

- increase the "other food reference implementation" in the standard range.

This standard replaced the previous version of the standard release.

-SN 0712-1997

-SN/T 0712-2010.

National standards for food safety Determination of 11 Herbicide Residues in Grain and Soybeans - Gas Chromatography - Mass Spectrometry

1 Scope

This standard specifies the method for the determination of 11 herbicides in grain and soybeans by gas chromatography-mass spectrometry.

2 Normative reference documents

The following documents are indispensable for the application of this document. For dated references, only the dated edition applies to this article Pieces. For undated references, the latest edition (including all modifications) applies to this document.

GB 2763 National Standard for Food Safety - Maximum Residue Limit of Pesticides in Foodstuffs GB/T 6682 Analytical laboratory water specifications and test methods

3 Principle

The residual herbicides in the sample were extracted with n-hexane and acetone, and the extract was concentrated by a neutral alumina solid phase extraction column or florisilide Solid phase extraction column purification, gas chromatography - mass spectrometry detection and confirmation, external standard quantitative.

4 Reagents and materials

Unless otherwise specified, all reagents are of analytical grade and water is in accordance with the primary water specified in GB/T 6682.

4.1 Reagents

4.1.1 Acetone (C3H6O). Chromatographic pure.

4.1.2 n-hexane (C6H14). pure chromatography.

4.1.3 Acetonitrile (CH3CN). Chromatographic Purification.

4.1.4 Sodium chloride (NaCl).

4.1.5 anhydrous sodium sulfate (Na2SO4). 650 °C burning 4 h, placed in the dryer to spare.

4.2 Solution preparation

4.2.1 n-Hexane - acetone solution (2 1, volume ratio). take.200 mL of n-hexane, add 100 mL of acetone, shake back.

4.2.2 n-hexane - acetone solution (9 1, volume ratio). take 900 mL of n-hexane, add 100 mL of acetone, shake back.

4.2.3 n-hexane - acetone solution (8 2, volume ratio. take 800 mL of n-hexane, add.200 mL of acetone, shake back.

4.3 Standards

4.3.1 11 kinds of herbicide standards. purity >= 95.0%.

4.4 Standard solution preparation

4.4.1 Standard stock solution. Pesticide standard is accurately weighed (see Appendix A), with n-hexane were prepared into a concentration of 100 µg/mL ~ 1000 µg/mL standard stock solution. Standard stock solution at -18 °C under the conditions of storage; if necessary, then diluted with n-hexane to the appropriate concentration of the standard Quasi-working fluid, stored at 0 °C ~ 4 °C.

4.5 Materials

4.5.1 Neutral alumina solid phase extraction column. 1000 mg, 6 mL. Before use with 3 mL of acetone in advance, 5 mL n-hexane activation, prepared use.

4.5.2 Fluoresa Silica Solid Phase Extraction Column. 500 mg, 6 mL. Before use with 3 mL of acetone in advance, 5 mL n-hexane activation, prepared use.

5 Instruments and equipment

5.1 Gas Chromatography-Mass Spectrometer (GC-MSD). Equipped with electron impact ionization source (EI).

5.2 Electronic balance. sensed 0.0001 g and 0.01 g.

5.3 Solid phase extraction device.

5.4 pulverizer.

5.5 Centrifuge, 5000r/min.

5.6 vortex mixer.

5.7 Rotary Evaporator.

5.8 homogenizer,.20000r/min.

5.9 Concentrated Bottle. 100 mL.

5.10 with a centrifuge tube. 15 mL, 50 mL.

5.11 anhydrous sodium sulfate column. 8.0 cm. min. 01 g ID) glass column with 5 cm high anhydrous sodium sulfate.

6 Preparation and storage of samples

6.1 Preparation of the sample

The sample was divided into four cents by dtex, and the sampling site was carried out according to GB 2763 Appendix A, all pulverized with a pulverizer and passed through a 2.0 mm of the round hole sieve, mix, are divided into two as a sample, sub-packaged into a clean vial, sealed and marked.

6.2 Sample storage

Samples stored at 0 °C ~ 4 °C below. During the operation of the sample preparation, the contamination of the sample or the change in the content of the residue should be prevented.

7 Measurement steps

7.1 Extraction

7.1.1 Rice, corn and wheat

Weigh the sample about 5 g (accurate to 0.01 g) in a 50 mL centrifuge tube, add 3 g of sodium chloride, 10 mL of water and 20 mL of n-hexane-and homogenized at 10 000 r/min for 2 min at 4 000 r/min for 5 min. The supernatant was dehydrated through an anhydrous sodium sulphate column at 100 ML concentrated bottles. And then 20 mL of n-hexane - acetone repeated extraction time, combined extract in the same 100 mL concentrated bottle, in 35 °C water bath with the rotary evaporator is concentrated to near dryness and dried with a nitrogen stream. Add 2mL n-hexane dissolved residue to be purified.

7.1.2 Soybeans

Weigh the sample about 5 g (accurate to 0.01 g) in a 50 mL centrifuge tube, add 5 g of anhydrous sodium sulfate and 20 mL of acetonitrile, 10 000 r/min homogeneous 2 min, centrifuged at 4 000 r/min for 5 min. The supernatant was transferred to a 100 mL concentrated flask. And then 20 mL B Nitrile once again, the combined extract in the same 100 mL concentrated bottle, 35 °C water bath with a rotary evaporator concentrated to near dry, and then nitrogen Flow dry. Add 2mL n-hexane dissolved residue to be purified.

7.2 Purification

7.2.1 Corn

The above sample solution was transferred to the neutral alumina solid phase extraction column, the flow rate was controlled at 1 mL/min ~ 2 mL/min, and the effluent was discarded.

Add 10 mL of n-hexane - acetone solution to control the flow rate of 1 mL/min ~ 2 mL/min, collecting eluent. The eluate was blown at 60 ° C After the instrument was dried, it was dissolved in 5 mL of n-hexane and analyzed by gas chromatography-mass spectrometry.

7.2.2 Rice, soybeans and wheat

A neutral alumina solid phase extraction column (1 cm high anhydrous sodium sulfate layer in the column) was mounted on a solid phase extraction vacuum suction apparatus, First with 6 mL of acetone - n-hexane mixture pre-elution extraction column, discard all the pre-eluent. The extract was added to neutral alumina for solid phase extraction in the column, the extract was completely eluted and the extract was eluted with 5 mL of acetone-n-hexane mixture to maintain a flow rate of 1.5 mL/min.

The whole effluent was blown to near dry at 45 ° C. With constant volume of n-hexane to 0.5 mL for GC-MS determination.

7.3 Determination

7.3.1 Gas Chromatography - Mass Spectrometry Reference Conditions

A) Column. DB-5ms quartz capillary column, 30 m × 0.25 mm (id), film thickness 0.25 µm or equivalent;

B) column temperature. the initial temperature of 100 °C for 1 min, to 15 °C/min rose to 260 °C, keep 15 min;

C) Inlet temperature. 250 ° C;

D) chromatographic - mass spectrometer interface temperature. 280 ° C;

E) Carrier gas. helium, purity greater than 99.999%, constant current mode, flow rate 1.0 mL/min;

F) Injection volume. 1 µL;

G) Injection method. splitless injection, 0.75 min after the opening valve;

H) ionization mode. EI;

I) Ionization energy. 70 eV J) ion source temperature. 230 ° C;

K) quadrupole temperature. 150 ° C;

L) Determination of the way. select the ion monitoring mode;

M) Select the monitoring ions (m/z). see Table 1 and Appendix B;

N) solvent delay. 5.0 min.

Table 1 Select the mass spectrometry parameters for the ion monitoring mode.

Channel time/min Select ion (amu) dwell time/ms 1 5.00 223,269,160,188,237,222,151,265,162,238,240,146 40 2 9.20 252,162,253,281,176,311,237,160,173,145,323,262,238 30 3 10.60 119,91,269,120,266,394,267,245,192,136,148,298 40

7.3.2 Determination and confirmation of chromatography

According to the content of the sample in the sample solution, the selected concentration and sample solution similar to the standard working solution. Standard working solution and sample solution the response value of the herbicide should be within the linear range of the instrument. Standard working solution and sample solution volume measurement.

If there is a chromatographic peak at the same retention time in the selective ion chromatogram of the sample solution with the standard working solution, the types of herbicides and their abundance ratios were confirmed. In the above-mentioned gas chromatography-mass spectrometry conditions, the sample in the sample is retained Between the standard working solution and the corresponding retention time deviation of ± 2.5%, and the sample of the measured substance relative abundance and concentration of the standard the relative abundance of the working solution is compared and the relative abundance allows the relative deviation not to exceed the range specified in Table 2, in the corresponding measured object. The reference retention time and gas chromatography-mass spectrometry ion chromatograms for 11 herbicide standards are shown in Appendix B and Appendix C in the C.1.

The maximum allowable error of relative ion abundance when using gas chromatography - mass spectrometry

7.4 Blank experiment

In addition to the sample, according to the above determination steps.

8 Results are calculated and expressed

The amount of each herbicide residue in the sample is calculated according to formula (1) xx xxx MA VcA IS Isi (1) the amount of each herbicide residue in the Xi sample is in milligrams per kilogram (mg/kg);

The peak area of each herbicide in the sample solution;

Cis The concentration of each herbicide in standard working fluid, in micrograms per milliliter (µg/mL);

Ais standard working fluid in the peak area of each herbicide;

V sample liquid final volume, in milliliters (mL);

M The final sample mass represented by the sample, in grams (g).

Note. The result of the calculation shall be deducted from the blank value. The result of the measurement shall be expressed as the arithmetic mean of the parallel measurement, and two valid digits shall be retained.

9 Precision

9.1 The ratio of the absolute difference between the two independent determinations obtained under reproducibility and its arithmetic mean (percentage) shall be in accordance with Appendix E requirements.

9.2 The ratio of the absolute difference between the two independent determinations obtained under reproducibility and its arithmetic mean (percentage) shall be in accordance with Appendix F requirements.

10% limit and recovery rate

10.1 Quantitation limits

The determination of 11 herbicides in rice, wheat, maize and soybean by this method was determined. The limit of quantification of various pesticides was 0.01 Mg/kg.

10.2 Recovery rate

The range of concentration and recovery of this method is given in Appendix D.

Relative abundance (base) 50% 20% to 50% 10% to 20% <=10% Allowable relative deviation ± 20% ± 25% ± 30% ± 50% Appendix A (Normative appendix)

11 Basic information on herbicide reference materials Table A.1

No. Herbicide name English name CAS number Chemical formula 1 acetochlor 34256-82-1 C14H20ClNO2 2 alachlor 15972-60-8 C14H20ClNO2 3 pentachioide esprocarb 85785-20-2 C15H23NOS 4 metolachlor 51218-45-2 C15H22ClNO2 5 paclitaxel pendimethalin 40487-42-1 C13H19N3O4

6 Butachlor 23184-66-9 C17H26ClNO2 7 fluoroamide flutolanil 66332-96-5 C17H16F3NO2 8 ethoxypramide pretilachlor 51218-49-6 C17H26ClNO2 9 rusted amine mepronil 55814-41-0 C17H19NO2

10 Fluorinated acyl chloride diflufenican 83164-33-4 C19H11F5N2O2 11 benzothioacetate mefenacet 73250-68-7 C16H14N2O2S Appendix B (Informative) 11 kinds of herbicide retention time, quantitative and qualitative selection of ions and determination of low limit table

Table B.1 Retention time, quantification and qualitative selection of 11 kinds of herbicides and determination of low limit table

No. pesticide name retention time/min Characteristic fragment ion (amu) Quantitative qualitative abundance ratio

1 Acetochlor 8.268 223 146,162,269 63. 100. 75. 9 2 alachlor 8.405 160 188,237,269 100. 84. 24. 9

3 Pentachlor 8.731 222 162,151,265 100. 67. 25. 12 4 isopropyl alachlor 8.910 162 238,240,146 100. 45. 14. 11 5 pendimethalin 9.408 252 162,253,281 100. 22. 10. 14

6 Butachlor 9.945 176 311,237,160 90. 100. 24. 7 7 fluoroamide 10.098 173 145,281,323 100. 27. 26. 13 8 propachlor 10.220 262 162,176,238 46. 100. 92. 73 9 rusted amine 10.937 119 91,269,120 100. 26. 18. 9

10 Fluoric acid Herb 11.493 266 394,267,245 100. 21. 16. 13

11 Benzylthioacetate 12.629 192 136,148,298 100. 25. 19. 8 Appendix C (Informative) 11 kinds of herbicides standard gas chromatography - mass spectrometry selective ion chromatogram 1 - Acetochlor; 2 - Pentachlor; 3 - Alachlor; 4 - Propellaben; 5 - Pentachlor; 6 - Butachlor; 7 - fluoroamide; 8 - propachlor; 9 - rust amine; 10 - phenanthraquinide; 11 - benzethonium chloride

Figure C.1 11 kinds of herbicides standard gas chromatography-mass spectrometry ion chromatogram

Appendix D

(Informative)

Sample concentration and recovery of the experimental data

Table D.1 Experimental data on the concentration and recovery of the sample

Chinese pass

Name

Add the recovery and precision range /% (add level of 0.01mg/kg ~ 2.0 mg/kg) Rice and wheat corn Recovery rate precision recovery rate precision recovery rate precision recovery rate precision

1 Acetochlor

87.1 ~

98.6

79.4 ~

100.7

1.7 to 8.4

82.5 ~

108.7

12.4

87.1 ~

105.2

2 alachlor

85.3 ~

106.5

12.1

83.1 ~

111.0

4.2.1

80.0 ~

108.3

2.5 to 8.7

75.3 ~

101.2

12.1

3 pod

80.5 ~

102.1

4.2.1 ~

76.5 ~

104.0

2.8 to 3.9

84.3 ~

101.6

1.1 ~ 5.8

81.6 ~

108.1

11.0

Isopropylidene

Grass

85.3 ~

111.8

85.6 ~

110.6

10.1

84.7 ~

100.9

2.2 to 7.9

88.0 ~

111.1

0.85 ~

Pentamethorphan

86.6 ~

104.1

10.5

77.3 ~

117.2

4.2.1

84.2 ~

107.1

5.5 to 8.8

85.6 ~

110.6

6 Butachlor

80.5 ~

94.7

4.2.1 ~

85.3 ~

106.7

5.4 to 6.9

86.8 ~

104.2

2.7 to 5.1

80.0 ~

101.2

0.92 ~

7 fluoroamide

84.9 ~

102.5

88.2 ~

107.6

1.7 to 5.6

82.4 ~

101.2

10.1

82.7 ~

105.3

8 propachlor

85.9 ~

110.6

82.1 ~

106.3

1.5 to 5.8

87.3 ~

107.1

4.2.1 ~

79.5 ~

105.3

9 rust amine

80.5 ~

99.7

10.2

89.4 ~

101.7

2.6 ~ 7.7

80.3 ~

101.1

2.4 to 6.2

75.3 ~

103.2

10.1

Pevofloxyl

Grass

76.7 ~

104.9

74.2.3 ~

102.5

10.2

72.4 ~

107.1

4.4 to 6.8

78.1 ~

102.7

10.3

Pendiyl

Grass

85.3 ~

107.2

4.2.1 ~

79.3 ~

112.5

2.5 to 8.4

75.8 ~

100.3

10.1

85.3 ~

107.2

Appendix E

(Normative appendix) Laboratory repeatability requirements

Table E.1 Laboratory repeatability requirements

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

Table F.1 Inter-laboratory reproducibility requirements

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

......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 9 pages — is available in the English PDF.

Referenced standards

Cited by

GB 2763-2026National food safety standard-Maximum residue limits for pesticides in food

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