GB 23200.33-2016Food safety national standard -- Determination of 110 pesticide residues in solution of solution of chlorpyrifos, picolafil and dipentrrole in food -- Gas chromatography-mass spectrometry (English PDF)

4.1 Reagents

4.1.1 Acetone (CH3COCH3). Chromatographic pure.

4.1.2 Dichloromethane (CH2Cl2).

4.1.3 Cyclohexane (C6H12).

4.1.4 Ethyl acetate (CH3COOC2H5).

4.1.5 Acetonitrile (C2H3N).

4.1.6 Toluene (C7H8).

4.1.7 Sodium chloride (NaCl).

4.1.8 anhydrous sodium sulfate (Na2SO4). before use at 650 °C for 4 hours, stored in a dryer, cooling and standby.

4.2 Solution preparation

4.2.1 Sodium chloride solution (15%, w/v). Weigh 15 g of sodium chloride, dissolve in 100 mL of water and shake well.

4.2.2 Cyclohexane-ethyl acetate (1 + 1, V/V). Take 100 mL of cyclohexane, add 100 mL of ethyl acetate and mix well.

4.2.3 acetonitrile - toluene (3 +1, V/V). take 300 mL of acetonitrile, add 100 mL of toluene, shake back.

4.3 Standards

4.3.1 Pesticide reference substance. List of reference substances is shown in Appendix A, Standard substance purity >=95%.

4.4 Pesticide standard solution

4.4.1 Standard stock solution. accurately weighed the appropriate standard (accurate to 0.1 mg), dissolved in acetone, prepared into a concentration of 500 µg/mL of the standard reserve solution, -18 °C frozen protected from light, valid for 3 months.

4.4.2 Mixed standard intermediate solution. 110 pesticides are divided into five groups, grouping see Appendix A. Remove a certain volume of standard reserves Solution with acetone prepared into 10 mg/L mixed standard solution, 4 °C cold storage, valid for 1 month.

4.4.3 Substrate mixed standard Working solution. Remove a certain volume of mixed standard solution, add to 7.1 to 7.2 after purification the blank sample matrix solution was mixed and fixed to 1.0 mL with acetone. Matrix mixed standard working solution should be used with the current distribution.

4.5 Materials

4.5.1 filter aid. celite 545, or equivalent.

4.5.2 Solid phase extraction column with graphitized non-porous carbon/amidopropylsilylated silylated silica gel. Envi-Carb/LC-NH2, 500 mg / 500 mg, 6 mL, or equivalent.

6.1 Preparation of the sample

500 g of the sample was taken and the sampling site was carried out according to GB 2763 Appendix A, pulverized with a pulverizer and passed through a 20 mesh sieve.

Mix well, into a clean container, sealed and identified.

6.2 Sample storage

Samples stored at 0 ~ 4 °C in dark. Sampling, preparation and preservation of the sample should be prevented from contamination or residual pesticide content changes the

7.1 Extraction

Weigh the sample 20 g (accurate to 0.01 g) in a conical flask and add 20 mL of water for 30 min. Add 80 mL of acetone, Placed on the oscillator for 30 min. Adding an appropriate amount of the filter aid to the suction filter, transferring the sample and the extract to the suction filter, Decontamination filter, and then 3 × 5 mL acetone washing conical flask and sample residue, combined extract and washing solution, concentrated at 40 °C to about 20 ML. The above solution was transferred to a separatory funnel and 50 mL of a 15% (w/v) aqueous solution of sodium chloride was added to the separatory funnel in turn, 50 mL of bis Methyl chloride, shaken for 5 min. After standing, the dichloromethane layer was collected and dehydrated with anhydrous sodium sulfate. Add 50 mL of methylene chloride. Repeat the above procedure for. Combined with anhydrous sodium sulfate dehydrated dichloromethane, 40 °C water bath rotation concentrated to near dry, and then dry with nitrogen. Cyclohexane-Ethyl acetate is set to 4.0 mL, to be purified.

7.2 Purification

7.2.1 Gel permeation chromatography purification

Place the solution to be purified in 7.1 on a gel chromatograph at a sample volume of 2.0 mL (equivalent to half the sample size), cyclohexane - ethyl acetate as the mobile phase at a flow rate of 3.0 mL/min, discard the 0 ~ 20 mL eluent, collect the 21 ~ 70 mL eluent, Water bath spin concentrated to near dry, and then dry with nitrogen. The residue was dissolved in 2 mL of acetonitrile-toluene solution.

7.2.2 Solid phase extraction purification

The Envi-Carb/LC-NH2 solid phase extraction column was placed on a solid phase extraction apparatus. Pre-leaching with 10 mL of acetonitrile-toluene solution. Will be passed by 7.2.1 the purified solution was transferred to the solid phase extraction column and the eluent was collected at the same time. The container was washed with 3 x 1 mL acetonitrile-toluene solution and transferred to solid phase extraction Take the column and adjust the device so that the eluent flow rate is about 2 mL/min. And then washed with 20 mL of acetonitrile-toluene solution solid phase extraction column, combined shower Lotion. In 40 ° C water bath rotation concentrated to near dry, and then dry with nitrogen. With acetone to 1.0 mL, determined by gas chromatography-mass spectrometry.

7.3 Determination

7.3.1 Gas Chromatography - Mass Spectrometry Reference Conditions

A) Column. DB-5MS (30m × 0.25mm × 0.25µm) quartz capillary column or equivalent;

B) Column temperature. 60 °C for 2 min, first to 25 °C/min temperature to 130 °C, and then heated to 4 °C/min to 180 °C, and then raised to 300 ° C at 6 ° C/min for 10 min.

C) Carrier gas. helium, purity >=99.999%, flow rate 1.0 mL/min;

D) Inlet temperature. 250 ° C;

E) Injection volume. 2 µL;

F) Injection mode. pulse splitless injection, pulse pressure 20 psi, keep 1.5 min;

G) electron impact ionization source. 70 eV;

H) ion source temperature. 230 ° C;

I) Quadrupole temperature. 150 ° C;

J) GC-MS interface temperature. 280 ° C;

K) solvent delay time. 7 min;

L) Select the ion monitoring. each pesticide choose a quantitative ion, 1 to 3 qualitative ions, according to the retention time of pesticide group detection.

Pesticide retention time, quantitative ions, qualitative ions See Appendix B. Refer to Appendix C for the grouping time and dwell time of each group to detect ions.

7.3.2 Qualitative determination

When a sample is measured, if a chromatographic peak coincides with the retention time of the reference substance in the sample quality chromatogram, and after subtracting the background, the selected ions in the corresponding spectrum of the chromatographic peaks (the deviation of the ion abundance ratio with the standard substance's abundance ratio satisfies the residual analysis), You can determine the presence of this pesticide in the sample.

7.3.3 Quantitative determination

In order to reduce the effect of matrix on quantitative results, this method uses blank sample solution to arrange matrix mixed standard working solution, external standard method Determination. The pesticide response in the sample should be within the linear range of the matrix mixed standard working solution. The method of reference material in the selection of various grain base Select ion monitoring GC-MS mass chromatograms see Appendix D.

7.4 Parallel test

Perform the parallel test of the same specimen according to the above procedure.

7.5 Blank test

In addition to not taking the sample, are in accordance with the above steps.

10.1 Quantitation limits

The method was applied to the determination of 110 pesticide residues in rice, brown rice, barley, wheat and maize, and the determination of various pesticides Low limit of 0.01mg/kg.

10.2 Recovery rate

Using this method, five kinds of rice, brown rice, barley, wheat and corn were added to the recovery experiment, the level of 0.01 mg/kg, 0.05 mg/kg, 0.1 mg/kg, and the recoveries of the 110 pesticides in the five foods are shown in Appendix E.

Appendix A

(Informative)

Basic information on pesticide reference materials

Table A.1 pesticide Chinese name, English name, CAS number, mixed standard solution group table

Serial number Chinese generic name English generic name CAS number Mixed standard dissolved Liquid grouping 1 allyl alcohol Allethrin 584-79-2 A

2 Diacrylamide Allidochlor 93-71-0 A

3 Amperavalin Ametryn 834-12-8 A

4 Anilofos 64249-01-0 A

5 Atrazine Atrazine 1912-24-9 A

6 Oxycyclic Azaconazole 60207-31-0 A

7 Paulin Phosphorus Azinphos-methyl 86-50-0 A

8 Bendafenine Benfluralin 1861-40-1 A 9 solution grasses Benoxacor 98730-04-2 A

10 Diclofenac Boscalid 188425-85-6 A

11 Ethyl bromothiophosphate Bromophos-ethyl 4824-78-6 A

12 Ethyl pyrimethanol sulfonate Bupirimate 41483-43-6 A

13 Buprofezin Buprofezin 69327-76-0 A

14 Butafenacil 134605-64-4 A

15 Thiophosphate Cadusafos 95465-99-9 A

16 Brix Carbosulfan 55285-14-8 A

17 Caramel 5234-68-4 A

18 Acaricides Chlorbenside 103-17-3 A

19 Chlorethoxyfos 54593-83-8 A 20 insects and insects nitrenapyr 122453-73-0 A

21 Acaricides Chlorfenson 80-33-1 B Chloride Chlorobazon 1698-60-8 B

23 Chloroanisole Chloroneb 2675-77-6 B

24 Chlorthal-dimethyl 1861-32-1 B

25 Clodinafop-propargyl 105512-06-9 B

26 Chloroformamide clomeprop 84496-56-0 B

27 Lactobacillus Cloquintocet-mexyl 99607-70-2 B

28 Cracks Cyanophos 2636-26-2 B 29 ring grass enemy Cycloate 1134-23-2 B

30 Cyclophosphamide Cyflufenamid 180409-60-3 B

31 Ophiopogon Diallate 2303-16-4 B

32 Wo Ling Ling Diclofop-methyl 51338-27-3 B

33 Pepsi Phosphorus Dicrotophos 141-66-2 B

34 Piper grass Dimepiperate 61432-55-1 B

35 Dimethoate 60-51-5 B 36 dimethomorphine Dimethomorph 110488-70-5 B

37 Bentonite Diofenolan 63837-33-2 B 38 dioxin Dioxathion 78-34-2 B

39 Diphenamidide 957-51-7 B

40 B-Phosulfide Disulfoton 298-04-4 B

41 Endosulfan-sulfate 1031-07-8 C 42 fluorocyclazole Epoxiconazole 106325-08-0 C

43 F-fenvalerate Esfenvalerate 66230-04-4 C

44 Ethylene Fentan Ethalfluralin 55283-68-6 C

45 Ethiophenes Ethion 563-12-2 C

46 Ethoxy Diclofenac Ethofumesate 26225-79-6 C Acetoxazole 153233-91-1 C 48 imidazole ketone Fenamidone 161326-34-7 C

49 Phenanthroline Fenamiphos 22224-92-6 C

50 Benzenepine sulfone Fenamiphos-sulfone 31972-44-8 C

51 Fenbuconazole 114369-43-6 C

52 Flies Phosphorus Fenchlorphos 299-84-3 C

53 Pyramidol ester 2 Fluacrypyrim 229977-93-9 C

54 Phenanthroline green fluazifop-butyl 69806-50-4 C 55 flufenacetamide Flufenacet 142459-58-3 C

56 Flumiclorac pentyl 87546-18-7 C

57 Flumioxazin 103361-09-7 C 58 oxalic acid Fluthiacet-methyl 117337-19-6 C.

59 Stryrosol Flutriafol 76674-21-0 C 60 thiazolyl phosphorus Fosthiazate 98886-44-3 C Stilbene Furilazole 121776-33-8 C 62 benzimidium ether Halfenprox 111872-58-3 C

63 Fluoropyrofen Haloxyfop-methyl 69806-40-2 C

64 Hexachlor Heptachlor 76-44-8 C

65 Hexachlorobenzene 118-74-1 C

66 Imazalil 35554-44-0 D

67 Indanofan 133220-30-1 D Indoxacarb 144171-61-9 D

69 Chlorzopicol Isazofos 42509-80-8 D 70 isoprocarb 2631-40-5 D 71 rice blast Ling Isoprothiolane 50512-35-1 D

72 Biphenoxazole acid Isoxadifen-ethyl 163520-33-0 D

73 Lactofen 77501-63-4 D

74 Diethylpyrrolidate Mefenpyr-diethyl 135590-91-9 D 75 azoxystine Mepanipyrim 110235-47-7 D

76 Metalaxyl 57837-19-1 D

77 Insects Methacrifos 62610-77-9 D 78 metronachlor metolachlor 51218-45-2 D

79 Phytophosphate Mevinphos 26718-65-0 D

80 Dihydroxylamine Napropamide 15299-99-7 D

81 Trichloromethylpyridine Nitrapyrin 1929-82-4 D

82 Fluorfen Norflurazon 27314-13-2 D

83 Oxyfluorfen 42874-03-3 D 84 pendimethalin 40487-42-1 D Phenothrin 26002-80-2 D

86 Phorate Phorate 298-02-2 D

87 Phosphamidon 13171-21-6 D

88 Piperophos 24151-93-7 D

89 Jasmine Prohydrojasmon 158474-72-7 D Toxicant Propachlor 1918-16-7 D 91 propanil 709-98-8 D

92 Propofos Piper Propaphos 7292-16-2 E

93 Aniline Ling Propham 122-42-9 E Pyralophosphate Pyrazophos 13457-18-6 E

95 Pyridine Pyriproxyfen 95737-68-1 E 96 picolone Pyroquilon 57369-32-1 E

97 Pentachlorobenzene Quintozene 82-68-8 E

98 Quizalofop-ethyl 76578-14-8 E

99 Silvanazole Simeconazole 149508-90-7 E 100 thiophosphate Sulprofos 35400-43-2 E

101 Ding Tillon Tebuthiuron 34014-18-1 E

102 Tetrachloronitrobenzene Tecnazene 117-18-0 E 103 oxazolamide Tolfenpyrad 129558-76-5 E

104 Triadimefon 43121-43-3 E

105 Triadimenol 55219-65-3 E

106 Wildhill Triallate 2303-17-5 E

107 Foliar Phosphorus Tribuphos 78-48-8 E

108 Tricyclazole 41814-78-2 E Destroy the XMC 2655-14-3 E

110 Benzoylamine Zoxamide 156052-68-5 E Note. The second column of the Chinese common name in italics is an isomer of the compound Appendix B (Informative) Mass spectrometric conditions for GC/MSD determination

Table B.1. Retention time of pesticides, quantitative ions and qualitative ions

Serial number Chinese generic name English generic name keep time Min Monitor ions 1 diacetophenanthrene Allidochlor 8.176 132 124 138 173 2-speed-off trans-Mevinphos 10.422 192 109 127 164 3-speed-off cis-Mevinphos 10.490 192 109 127 164

4 Trichloromethylpyridine Nitrapyrin 10.956 196 194 198

5 Aniline Ling Propham 11.176 179 93 137

6 Insects Methacrifos 11.968 208 125 180

7 Chloroanisole Chloroneb 12.153 191 206 208

8 Ding Tillon Tebuthiuron 12.480 156 157 171 9 isoprocarb 12.790 121 91 136

10 Elimination of Granville XMC 13.344 122 107 179

11 Tetrachloronitrobenzene Tecnazene 13.966 261 203 215 Propoxlor 14.363 120 176 211

13 Chlorethoxyfos 14.582 299 153 301 Cycloate 15.089 154 83 215 Ethanolluralin 15.372 276 316 292

16 Pepsi Phosphorus Dicrotophos 15.688 127 193 237

17 Bindalfen Benfluralin 15.897 292 264 276

18 Sulfur Phosphorus Cadusafos 16.236 159 214 270 Swallow enemy diallate 1 16.390 234 128 236 Potentrol Phorate Hexachlorobenzene 16.598 284 282 286

22 Swallow enemy Diallate 2 16.782 234 128 236

23 Dimethoate 17.125 87 125 229 24 solution of oxazolam Furilazole 17.439 220 222 262

25 Pentachlorobenzene Quintozene 17.740 295 237 249

26 Atrazine 17.753.200 173 215 27 dioxin Dioxathion 18.081 270 197 153

28 Cannophilia Cyanophos 18.308 243 109 125 29 picolone Pyroquilon 18.462 173 130 144 Phosphamidon 1 18.646 127 138 264

31 B and P Disulfoton 19.062 274 88 142 32 jasmine Prohydrojasmon 19.164 83 153 184

33 Chlorzopicol Isazophos 19.181 257 161 285

34 Tri-allate 19.392 268 270 143 35 solution of oxalazine Benoxacor 19.770 120 259 261 Phosphamidon 2 20.241 127 138 264 37 propanil 20.351 163 161 217

38 Silvanazole Simeconazole 20.829 121 211 278 39 heptachlor 21.003 272 237 274

40 Metalaxyl Metalaxyl 21.148 206 220 234 Amoxicide Ametryn 21.179 227 185 212 Potato Phenanthrene

43 Ethoxy Diclofenac Ethofumesate 21.896 207 161 286 44 metolachlor 22.268 162 238 240 45 methyl chlorophthalate Chlorthal-dimethyl 22.506 301 299 332 46 flufenacetamide Flufenacet 22.760 151 123 211 Glucosamine Triadimefon 22.772 208 181 210

48 Diphenamidate Diphenamid 23.191 167 165 239 49 thiazolophos 50 thiazolyl phosphorus Fosthiazate 2 23.313 195 227 283 51 pendimethalin 23.572 252 162 191 281

52 Allyl alcohol Allethrin 1 23.991 123 107 136

53 Allyl alcohol 2 Allethrin 2 24.035 123 107 136

54 Allyl alcohol Allethrin 3 24.185 123 107 136

55 Allyl alcohol Allethrin 4 24.231 123 107 136

56 Papyrus Dimepiperate 24.287 119 145 263

57 Triadimolol Triadimenol 1 24.297 168 112 128

58 Benzoylamine Zoxamide 1 24.378 187 242

59 Triadimenol 2 24.576 168 112 128

60 Ethyl bromothiophosphate Bromophos-ethyl 24.649 359 303 357

61 Acaricides Chlorbenside 24.668 125 127 268

62 Propolis Piper Propolis 24.823 220 262 304

63 Fluoroproline Haloxyfop-methyl 24.824 316 288 375

64 Azoxystine Mepanipyrim 25.256 222 221 223

65 Stryzolol Flutriafol 25.307 123 164 219

66 Diclofenac Napropamide 25.418 271 128 171

67 Phenanthroline Fenamiphos 25.445 303 217 288

68 Acaricidal Chlorfenson 25.540 177 302 304

69 Imazalil 25.585 215 173 217 70 tricyclazole Tricyclazole 25.591 189 161 162

71 Rice Blast Ling Isoprothiolane 25.722 204 231 290

72 Dephosphorites Tribuphos 26.066 169 202 258

73 Carpentry Carboxin 26.194 235 143

74 Buprofezin Buprofezin 26.197 105 172 305

75 Ethoxyphenanthrene Oxyfluorfen 26.202 252 300

76 Ethanol Phenol Sulfonate Bupirimate 26.209 208 273

77 Oxycyclazole Azaconazole 26.271 217 219 78 insects and insects nitrenapyr 26.497 59 247 408

79 Cyclofluramine Cyflufenamid 26.587 118 91 412

80 Phenanthroline Lentin Fluazifop-butyl 26.866 282 254 383 Amoxicine Ethanol 27.361 231 153 384

82 Pyramidol ester Fluacrypyrim 27.695 145 189 204 83 thiophosphate Sulprofos 27.866 322 156 280 Isoxadifen-ethyl 28.081 204 222 294

85 Fluorfenin Norflurazon 28.210 303 145 173

86 Endosulfan sulfate 28.334 272 387 422

87 Bentonite Diofenolan 1 28.386 186 225 300 Chlorobazon Chlorobazon 28.440 221 220 223 Amoxicillin Diofenolan 2 28.591 186 225 300

90 Clodinafop-propargyl 28.607 266 238 349

91 Strawberry Diclofop-methyl 29.054 253 281 340 342 92 fluorocyclazole Epoxiconazole 29.409 192 165 194

93 Benzoylamine Zoxamide 2 29.442 187 189 258

94 Diethyl pyrrolidine Mefenpyr-diethyl 29.529 253 255 299

95 Benzenepine sulfone Fenamiphos-sulfone 29.769 320 292 335

96 Butylcyclopedia Carbosulfan 29.843 160 118 163 Piperophos 30.183 122 140 320

98 Cloquintocet-mexyl 30.296 192 193 194

99 Acetoxazole Etoxazole 30.372 300 330 359 100 imidazole ketone Fenamidone 30.426 238 268

101 Indenone Indanofan 30.540 139 174 310 Erythrite Anilofos 30.582 226 125 184

103 Chloroformamide Clomeprop 30.762 288 120 148 Phenothrin 1 30.887 123 183 350 Phenothrin 2 31.085 123 183 350

106 Insulat...