SN/T 5221-2019Determination of chlorantraniliprole residues in foods of plant origin for export (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

The first method of this standard specifies the gas chromatography-mass spectrometry method for the determination of methoprene residues in foods of plant origin for export. Second law A liquid chromatographic method for the determination of methoprene residues in grains has been established.

This standard applies to peaches, pears, cucumbers, potatoes, eggplants, apples, papaya, green peppers, lettuce, rice and other plant-derived foods Determination and confirmation of chlorantraniliprole residues.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 6682 Analytical laboratory water specifications and test methods Method 1 Liquid Chromatography-Mass Spectrometry/Mass Spectrometry

3 Method summary

The residual chlorantraniliprole in the sample was extracted with acetonitrile, and the extract was purified by an NH2 amino solid-phase extraction column, and separated by a C18 column.

Measured objects are detected by electrospray ionization, positive ion scanning and multiple reaction monitoring mode (MRM), and external standard method is used for quantification.

4 Reagents and materials

Except for special instructions, the reagents used are all analytically pure, and the water is first-grade water that meets the requirements of GB/T 6682.

4.1 Acetonitrile (CH3CN). chromatographic grade.

4.2 Methanol (CH3OH). chromatographic grade.

4.3 Formic acid (HCOOH). chromatographic grade.

4.4 Anhydrous magnesium sulfate (MgSO4).

4.5 Sodium chloride (NaCl).

4.6 Mixed powder of anhydrous magnesium sulfate and sodium chloride (1.1). Weigh 50 g of anhydrous magnesium sulfate and 50 g of sodium chloride powder and mix them in a beaker.

Combine evenly, ready for use now.

4.7 0.1% formic acid aqueous solution. accurately pipette 1 mL of formic acid (4.3) into a 1000 mL volumetric flask, add water to the volume and mix well spare.

4.8 Standard material. Chlorantraniliprole (CAS No. 500008-45-7), the purity is greater than 99%.

4.9 Standard stock solution. accurately weigh an appropriate amount of chlorantraniliprole standard substance (4.8), and use methanol (4.2) to prepare the concentration to the 100 mg/L standard stock solution should be stored below -18°C and protected from light.

4.10 Intermediate standard solution. draw an appropriate amount of the above standard stock solution (4.9) and dilute with acetonitrile (4.1) to prepare a 1.0 µg/mL intermediate the standard solution should be stored below 4°C and protected from light.

4.11 Standard working solution. draw an appropriate amount of intermediate standard solution (4.10), and use a blank sample solution to prepare a standard working solution of appropriate concentration Solution, ready to use.

4.12 Amino solid phase extraction column. 6 mL, 1 g or equivalent, activate with 6 mL acetonitrile (4.1) before use, and keep the column moist.

4.13 Microporous membrane. 0.22 mm, organic phase type.

5 Apparatus and equipment

5.1 Liquid Chromatography Tandem Quadrupole Mass Spectrometer. Distributed Spray Positive Ion Source (ESI).

5.2 Analytical balance. Sensitivity 0.1 mg and 0.01 g.

5.3 Vortex mixer.

5.4 Homogenizer.

5.5 Centrifuge. the speed is greater than 3 000 r/min.

5.6 Nitrogen blowing concentrator.

5.7 Centrifuge tube. 50 mL PTFE centrifuge tube.

5.8 Solid phase extraction device.

6 Sample preparation and storage

During the sample preparation process, sample contamination or changes in residue content should be prevented.

7 Analysis steps

8 Calculation and expression of results

Calculate the residual amount of chlorantraniliprole in the sample according to formula (1).

X-Chlorantraniliprole residue in the sample, in milligrams per kilogram (mg/kg);

c-The concentration of chlorantraniliprole obtained from the standard working curve, in micrograms per milliliter (µg/mL);

c0-the concentration of chlorantraniliprole obtained in the blank test, in micrograms per milliliter (µg/mL);

V --The final volume of the sample solution, the unit is milliliters (mL);

m - The sample volume represented by the final sample solution, in grams (g).

Note. The calculation result should be deducted from the blank value, and the measurement result shall be expressed by the arithmetic mean of parallel determinations, and two significant digits shall be retained.

9 Method quantification limit and recovery rate

10 Method summary

Acetonitrile (4.1) was used to extract the residual chlorantraniliprole in the sample, and the extract was purified by an amino solid phase extraction column (4.12) to the C18 column separates the analyte for the determination of a high performance liquid chromatograph equipped with a two-tube array detector or an ultraviolet detector, outside...