GB 29699-2013Determination of Clopidol residues in chicken muscle by Gas Chromatography-mass Spectrometric method (English PDF)

6.1 Preparation of the sample

Fresh or thawed take appropriate blank or test tissue, minced, and homogenized.

--- the test sample taken after homogenization, as the feed try.

--- blank sample taken after homogenization, as a blank sample.

--- blank sample taken after homogenization, adding a suitable concentration of the standard working solution, is added as a blank sample.

Save 6.2 sample

Or less at -20 °C.

Determination Step 7

7.1 Preparation of matrix-matched standard curve

The precise amount of 1µg/mL clopidol appropriate amount of working standard solution, were added to the extracted, the purification step of the processing parts of the blank sample 6 Eluate by derivatization, to obtain the concentration of 5,10,20,100,250 and 500µg/L of matrix-matched series of standard solution, gas phase color Spectroscopy - mass spectrometry. To measure peak area for the vertical axis, corresponding to the concentration of standard solution as abscissa, the standard curve. Seeking regression equation and the correlation coefficient.

7.2 Extract

Sample Weigh 5g ± 0.05g, in 50mL polypropylene centrifuge tube, acetonitrile was added 10mL, homogeneous 1min, oscillation 20min. 4 °C, 6000r/min centrifugal 10min, the supernatant, the residue was extracted with acetonitrile is repeated once 10mL. The combined supernatant twice, adding isopropanol 5mL, 50 deg.] C at a rotary evaporator to near dryness. The residue was dissolved with acetonitrile standby 5mL.

7.3 Purification

Basic alumina column activated with 15mL acetonitrile, taking stock solution through the column, the natural flow of dry acetonitrile was added 10mL, collecting eluate, 50 deg.] C and blown dry with nitrogen.

Derived 7.4

The residue was dissolved in toluene was added 100 L, 100 L adding derivatizing agent, seal, 80 °C derivatization 1h. Cooling, toluene was added 800 L, for Gas Chromatography - Mass Spectrometry.

7.5 Determination

7.5.1 Gas chromatographic conditions

7.5.1.1 Column. phenylmethyl silicone capillary column (30m × 0.25mm, film thickness 0.25µm), or equivalent person.

7.5.1.2 flow. 0.8mL/min.

7.5.1.3 temperature program. 100 °C 1min, to a rate of 30 °C/min heating to 200 °C, then to 5 °C/min was heated to 205 °C, Paul Temperature 1min, then 30 °C/min was heated to 280 °C, maintained 1min.

7.5.1.4 Interface Temperature. 280 °C.

7.5.1.5 Inlet temperature. 220 °C.

7.5.1.6 Injection mode. splitless.

7.5.1.7 Injection volume. 1µL.

7.5.2 MS conditions

7.5.2.1 ionization mode. electron ionization (EI).

7.5.2.2 Ion source temperature. 230 °C.

7.5.2.3 Scan mode. Selected ion monitoring, qualitative ion m/z212,214,248 and 263, qualifier ion m/z248.

7.5.3 Assay

7.5.3.1 Qualitative determination

Samples with the standard peak retention time is not more than 2s.

Detecting at least four characteristic ions, i.e. 212,214,248,263, wherein.

248 base peak ion is selected;

SIM relative intensity of 214,263 (base peak ratio) of not more than 30% relative intensity corresponding to a standard average of selected ion;

SIM 212 relative intensity ratios (base peak) does not exceed the corresponding selection criteria relative ion intensity of 25% of the average.

Clopidol trimethylsilyl ether derivative spectrum and the extracted ion chromatogram, add chicken and chicken clopidol blank tissue extracts Ion chromatogram given in Appendix A.

Quantitative determination 7.5.3.2 Take the sample solution and the volume of matrix blank sample standard solutions and other injections of measured peak area base peak (m/z248) (peak height) as a single point Multi-point calibration, external standard. Matrix blank sample solution and the standard solution the response value clopidol linear range of the instrument to be detected Around inside.

7.6 Blank test

But without addition of the sample, the same steps employed in parallel operation.

Calculation and Expression of Results 8 Residues of the specimens clopidol (µg/kg) according to formula (1).

A × cS × V

AS × m

Where.

Concentration of the sample of X---- clopidol, in units of micrograms per kilogram (µg/kg);

Sample A --- clopidol peak area;

--- the AS peak area of standard solution of clopidol;

Standard solution concentration cS --- clopidol, in units of micrograms per liter (µg/L);

V --- final sample volume in milliliters (mL);

m --- try supply feed mass in grams (g).

Note. The blank value should be subtracted from the results, expressed as the arithmetic mean of the measurement result measured parallel to three significant figures.

9.1 Sensitivity

The detection limit of the method was 1µg/kg, the limit of quantitation of 5µg/kg.

9.2 Accuracy

This method of adding 5µg/kg ~ 100µg/kg on recovery levels of 60% to 120%.

9.3 Precision

The relative standard deviation of the method <=20%, inter-assay relative standard deviation <=20%.

Appendix A

Chromatogram

Figure A.1 clopidol ion chromatogram of the standard solution (10ng/mL)

Figure A.2 chicken muscle tissue ion chromatogram of blank sample

Figure A.3 chicken muscle tissue sample blank add clopidol ion chromatogram (10µg/kg)