GB 23200.34-2016Food safety national standard -- Determination of 65 Pesticide Residues in Foods by Liquid Chromatography-Mass Spectrometry / Mass Spectrometry (English PDF)

4.1 Reagents

4.1.1 Methanol (CH3OH). High performance liquid chromatography grade.

4.1.2 acetonitrile (CH3CN). high performance liquid chromatography grade.

4.1.3 Acetone (C3H6O). High performance liquid chromatography grade.

4.1.4 dichloromethane (CH2Cl2). high performance liquid chromatography grade.

4.1.5 Toluene (C7H8). High performance liquid chromatography grade.

4.1.6 Formic acid (HCOOH). High performance liquid chromatography grade.

4.1.7 Ammonium acetate (CH3COONH4).

4.1.8 Sodium chloride (NaCl).

4.1.9 anhydrous sodium sulfate (Na2SO4). 650 °C burning 4 h, placed in the dryer cooling standby.

4.1.10 filter aid. celite 545, or equivalent.

4.2 Solution preparation

4.2.1 15% aqueous solution of sodium chloride. accurately weighed 15 g of sodium chloride dissolved in 100 mL of water.

4.2.2 0.1% formic acid aqueous solution (containing 0.5 mmol/L ammonium acetate). Accurately measure 1 mL of formic acid and weigh 0.0386 g of ammonium acetate at 1 L capacity Bottle, the water volume to 1 L.

4.2.3 SPE solution. 90 mL of acetonitrile by adding 30 mL of toluene, mix well.

4.3 Standards

4.3.1 Reference substance. 65 kinds of pesticide standard substance, purity >= 95%. See Appendix A for standard information.

4.4 Standard solution preparation

4.4.1 Standard stock solution. Accurately weigh the appropriate standard (accurate to 0.0001 g), dissolved in methanol to prepare a concentration of 100 µg/mL of the standard stock solution, -18 °C frozen protected from light.

4.4.2 intermediate standard solution. accurate removal of 1 mL standard stock solution) in a 10 mL volumetric flask, with a fixed volume of methanol to the standard, prepared into concentrated Degree of 10 µg/mL in the middle of the standard solution, 4 °C cold storage.

4.4.3 mixed standard working solution. according to the need to use the standard solution of methanol diluted to the appropriate concentration of mixed standard working solution, now with the current distribution.

4.5 Materials

4.5.1 Graphitized non-porous carbon/amidopropylsilylated silylated silica gel as a solid phase extraction column. Envi-Carb/LC-NH2 500 mg/500 Mg, 6 mL, or equivalent.

4.5.2 Microporous membrane. 0.22 µm, organic phase.

6.1 Preparation of the sample

Approx. 500 g of representative samples taken from the original sample, sampled at GB 2763 Appendix A, pulverized with pulverizer and made all through the 20 mesh sample sieve, mixed evenly, are divided into two, respectively, into the clean container as a sample, sealed, and marked Remember.

6.2 Sample storage

Store the sample at 4 ° C and keep it in dark.

During the operation of the sample preparation, the sample should be protected from contamination or changes in the content of the residue.

7.1 Extraction

Approximately 10 g of sample (accurate to 0.01 g) was weighed in a 300 mL Erlenmeyer flask. Add 10 mL of water, put it aside for 30 min, then add 40 ML acetone, shock extraction 30 min. The sample and extract transferred to the filter funnel (has been added the right amount of filter aid), decompression pumping, the filtrate was collected in 100 mL pear bottles. And then 3 × 5 mL acetone washing conical flask and sample residue, the combined filtrate, and at 40 °C decompression Concentrated to about 10 mL. The solution was transferred to a 125 mL separatory funnel, followed by the addition of 30 mL of aqueous sodium chloride solution and 30 mL of dichloromethane and the mixture was allowed to stand for 10 min. After standing for 20 min, the dichloromethane layer was taken. Then add 30 mL of methylene chloride in the separatory funnel, the liquid distribution the methylene chloride layers were combined. The methylene chloride solution was dehydrated by anhydrous sodium sulfate and then concentrated to near dryness at 40 ° C under reduced pressure. After drying in nitrogen, Dissolved in 2 mL SPE solution to be purified.

7.2 Purification

The solid phase extraction column was pre-rinsed with 10 mL of SPE solution and transferred to the sample extract to collect the effluent. And then 30 mL of SPE solution the solid phase extraction column was washed and the effluent was combined. The whole solid phase extraction purification process controls the flow rate not to exceed 2 mL/min. The effluent was at 40 ° C Under the decompression concentrated to near dry, nitrogen dry. The residue was first dissolved in 0.4 mL of acetonitrile and then fixed to 1 mL with 0.1% formic acid in water After mixing, over 0.22 µm microporous membrane for instrument testing.

7.3 Preparation of mixed matrix standard solution

Weigh 5 copies of about 10 g of blank sample (accurate to 0.01 g) in 300 mL Erlenmeyer flask, according to the standard curve final volume concentration Add the intermediate standard solution or mix the standard working solution, the remaining operation with 7.1 and 7.2.

7.4 Determination

7.4.1 Liquid Chromatographic Reference Conditions

7.4.1.1 Column. CAPCELL PAK C18, 2.0 mm × 150 mm (id), 5 µm, or equivalent.

7.4.1.2 Mobile phase. A. Acetonitrile, B 0.1% formic acid aqueous solution. The gradient elution conditions are shown in Table 1 and Table 2.

Table 1 ESI Mode Liquid Chromatography Elution Conditions

Time/min A /% B /%

0 ~ 2 10 90

2 ~ 10 10 ~ 55 90 ~ 45 10 ~ 30 55 ~ 90 45 ~ 10 30 to 30.1 90 to 10 10 to 90 30.1 to 35 10 90

Table 2 ESI-Mode Liquid Chromatography Elution Conditions

Time/min A /% B /%

0 ~ 4 10 ~ 90 90 ~ 10 4 ~ 6 90 10 6 to 6.1 90 to 10 10 to 90 6.1 to 10 10 90

7.4.1.3 Column temperature. 40 ° C.

7.4.1.4 Flow rate. 0.2 mL/min.

7.4.1.5 Injection volume. 10 µL.

7.4.2 Mass spectrometry reference conditions

See Appendix B, Table B.1 and Table B.2. Wherein the purity of nitrogen and argon is greater than or equal to 99.999%.

7.4.3 Determination and confirmation of chromatography

According to the content of pesticide in the sample solution, the mixed medium standard solution with similar peak area is selected, and the mixed matrix standard solution and sample solution the volume of the sample in the mixed matrix standard solution and the pesticide in the sample solution should be within the linear range of the instrument detection.

Under the same experimental conditions, the mass retention time of the substance to be tested in the sample was the same as that of the mixed matrix standard solution and the background the selected ions in the sample mass chromatogram showed a comparison of the abundance of the selected ions compared to the mixed substrate standard solution.

If the value is within the allowable range (the allowable range is shown in Table 3), it is determined that there is a corresponding analyte in the sample. Under the above chromatographic conditions, the retention time of pesticides and their monitoring ions (m/z) are given in Appendix B, Table B.2. The multi-reaction monitoring chromatogram of the standard is shown in Appendix C, Figure C.1 and Figure C.2.

Table 3 Maximum allowable error of relative ion abundance using liquid chromatography-mass spectrometry/mass spectrometry

7.5 Blank experiment

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

10.1 Quantitation limits

The quantitative limits of this method are given in Appendix D.

10.2 Recovery rate

The recovery of this method is given in Appendix D.

Appendix A

(Normative appendix) Standard substance information

Table A.1 Basic information on 65 pesticides

English name Chinese name CAS number Molecular formula Molecular weight structure Aldoxycarb Oxyethoxylate 1646-88-4 C7H14N2O4S 222.2586 NO HN Azoxystrobin 131860-33-8 C22H17N3O5 403.3934 OO Bensulide Scavenging Water 741-58-2 C14H24NO4PS3 397.50166 NH Butroxydim Butoxfen 138164-12-2 C24H33NO4 399.53 NO OH Bipenazate Biphenylazide 149877-41-8 C17H20N2O3 300.36 NHNH OCH3 COOCH (CH3) 2 Buprofezin 69327-76-0 C16H23N3OS 305.26 NC (CH3) 3 CH (CH3) 2 Carboxin Czochralski 5234-68-4 C12H13NO2S 235.3 S O CH3 NH Carbofuran-3OH 3-hydroxy carbofuran 16655-82-6 C12H15NO4 237.26 NH HO Cleasmethrin 99129-21-2 C17H26ClNO3S 359.9103 OH Cl Cyazofamid Cyazofuran 120116-88-3 C13H13ClN4O2S 324.78 Cl SN Cycloxydim thioketone 101205-02-1 C17H27NO3S 325.4652 OH Carpropamid cyclopropionate 104030-54-8 C15H18Cl3NO 334.67 Cl Cl Cl Chlorfluazuron fluoxetine 71422-67-8 C20H9Cl3F5N3O3 540.6604 Cl Cl Cl OOF Chloroxuron Bacillus sp. 1982-47-4 C15H15ClN2O2 290.7487 Cl Chromafenozide Cyclohexyl Acetate 143807-66-3 C24H30N2O3 394.51 OO Clothian Plasmothanine 205510-53-8 C6H8ClN5O2S 249.67 N.

Cumyluron Diphenyl Long 99485-76-4 C17H19ClN2O 302.8029 Cl HN HN Daimuron Klebshan 42609-52-9 C17H20N2O 268.3578 N Dimethirimol Dimethanol 5221-53-4 C11H19N3O 209.2906 HO Diclobutrazol benzyl chloride triazole alcohol 75736-33-3 C15H19Cl2N3O 328.2406 Cl Cl OHNN Diflubenzuron 35367-38-5 C14H9ClF2N2O2 310.6871 N FOO Cl Diuron Diuron 330-54-1 C9H10Cl2N2O 233.0968 Cl Cl Ethipar Bipyrantin 181587-01-9 C13H9Cl2F3N4OS 397.2 FN Cl Cl H2N Fipronil 120068-37-3 C12H4Cl2F6N4OS 437.1462 Cl Cl H2N Fluazinam Fluorazidine 79622-59-6 C13H4Cl2F6N4O4 465.0954 N.

Fluazuron Dipyridine 86811-58-7 C20H10Cl2F5N3O3 506.2153 N Cl Cl HN FF Flufenoxuron Fipronil 101463-69-8 C21H11ClF6N2O3 488.7729 F NH NH O Cl Flusulfamide Sulfonamide 106917-52-6 C13H7Cl2F3N2O4S 415.1705 Cl FS Cl N.

Fenothiocarb 62850-32-2 C13H19NO2S 253.3586 Fenpyroxella Ferimzone Azoxazone 89269-64-7 C15H18N4 254.334 HN Fluiaturon Flourulonide 2164-17-2 C10H11F3N2O 232.2049 N.

Fluridone Flutidone 59756-60-4 C19H14F3NO 329.3209 Furathiocarb 65907-30-4 C18H26N2O5S 382.4738 O ON Hexaflumuron fluoride bellourea 86479-06-3 C16H8Cl2F6N2O3 461.1472 NH NH O Cl Cl FF Imazamethabenz-methyl Methyl oxalate 81405-85-8 C16H20N2O3 576.7 (288.35) Inbaenfide Anti - amide 82211-24-3 C19H15ClN2O2 338.7927 OH Cl Iprodione Isozyme 36734-19-7 C13H13Cl2N3O3 330.17 N Cl Cl Indoxacarb Indoxacillin 144171-61-9 C22H17ClF3N3O7 527.83 NN O CO2CH3 CO2CH3Cl OCF3 Imidacloprid 138261-41-3 C9H10ClN5O2 255.6633 Cl NH NN Isocyanon heterozygous 55861-78-4 C10H17N3O2 211.2632 HN NO Isoxaflutole isoxazolone 141112-29-0 C15H12F3NO4S 359.32 Lufenuron lucidum urea 103055-07-8 C17H8Cl2F8N2O3 511.155 OO Cl O Cl FF Methabenzthiazuron methyl benzene thiophene 18691-97-9 C10H11N3OS 221.2764 NN Metamitron Benzenocarbazone 41394-05-2 C10H10N4O 202.21 N NN O NH2 CH3 Methoxyfenozide Methoxy Hydrazide 161050-58-4 C22H28N2O3 368.4748 O Napropamide Dexamethasone 15299-99-7 C17H21NO2 271.39 O CH CH3 N (CH2CH3) 2 Novaluron 126714-46-6 C17H9ClF8N2O4 492.7093 OO Cl FF FF Oxpoconazole Oxidazole 134074-64-9 C19H24ClN3O2 361.87 OO Cl Oxaziclomefone oxadiazone 153197-14-9 C20H19Cl2NO2 376.28 Cl Cl Phoxim 14816-18-3 C12H15N2O3PS 298.29586 N Piperonylbutoxide synergist ether 51-03-6 C19H30O5 338.443 Pyraclostrobin Pyrethromycin ester 175013-18-0 C19H18ClN3O4 387.82 Cl N Pyrazolynate pyrazole 58011-68-0 C19H16Cl2N2O4S 439.3124 Cl Cl N OS Pyrazoxyfen Benzyl oxalate 71561-11-0 C20H16Cl2N2O3 403.264 Cl Cl Pinecuron. Chinese Journal of Pharmacoepidemiology] Cl NH Propoxlor 1918-16-7 C11H14ClNO 211.69 N COCH2Cl CH (CH3) 2 Pyriproxyfen Pyridyl ether 95737-68-1 C20H19NO3 321.4 NO CH CH3 CH2 Quizalofop-ethyl quinoxaline 100646-51-3 C19H17ClN2O4 372.8 N NO Cl O Spirodiclofen spironolactone 148477-71-8 C21H24Cl2O4 411.33 ClCl Tebufenozide Hydrazine 112410-23-8 C22H28N2O2 352.4754 Teflubenzuron fluorophenyl urea 83121-18-0 C14H6Cl2F4N2O2 381.1132 F NH NH Cl F F Cl Thiadinil Thiadiazole 223580-51-6 C11H10ClN3OS 267.7 Cl Thiacloprid Thiamethoxine 111988-49-9 C10H9ClN4S 252.72 Cl Thiamethoxam 153719-23-4 C8H10ClN5O3S 291.71 NN Cl N.

Appendix B

(Informative)

Mass spectrometry conditions B.1 Mass spectrometry conditions are given in Table B.1.

Table B.1 Mass spectrometry conditions

Ionization method ESI ESI-Capillary voltage 3.0 kV 2.8 kV the source temperature is 120 ° C the solvent temperature was 350 ° C Taper hole air nitrogen, 100 L/h Solvent gas stream nitrogen, 600 L/h Collision air pressure argon, 2.40 × 10-6 Pa Monitoring mode multiple reaction monitoring B.2 Multiple reaction monitoring conditions are shown in Table B.2.

Table B.2 Multiple reaction monitoring conditions

Serial number English name Chinese name Ionization mode ESI Mother ion M/z Ion M/z when staying Room/s Taper hole Voltage / V collision energy / EV when retained Room/min

1 Carpropamid plus normal amine 335.9 102.7 * 0.1 35 40 17.50 197.8 0.1 35 12

2 Chlorfluazuron fluoxetine 541.9 385 * 0.1 30 22 23.89 157.7 0.1 30 20

3 Chloroxuron

110.6 * 0.1 30 40

13.90

217.9 0.1 30 22

4 Chromafenozide Cyclohexanoic Acid Hydrazide 395.3 174.9 * 0.1 20 18 15.63 339.1 0.1 20 8

5 Clothian Netherfluramine 249.9 168.8 * 0.1 22 10 7.89 131.7 0.1 22 15

6 Cumyluron diphenyl Long 303.2 184.8 * 0.1 30 13 14.16 124.6 0.1 30 30

7 Diclobutrazol Benzyl Chlorotriazole Alcohol 328 69.9 * 0.1 30 20 14.93 158.6 0.1 30 35

8 Diflubenzuron dexamethasone 311 157.7 * 0.1 25 13 15.20 140.7 0.1 25 30

9 Diuron Diuron 232.9 71.7 * 0.1 30 13 11.95 159.7 0.1 30 25

10 Ethiprole

350.8 * 0.1 28 18

13.27

254.8 0.1 28 33