This standard specifies the determination method for dicofol residues in tea leaves, fruits and edible vegetable oils. This standard is applicable to the determination of dicofol residues in tea leaves, fruits and edible vegetable oils. GB/T 5009.176-2003 Determination of dicofol residues in tea leaves, fruits and edible vegetable oils GB/T5009.176-2003 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
GB/T5009.176-2003
Determination of dicofol residues in tea, fruits and edible vegetable oils
Detcrmination of dicofol residues in ted, fruits.edible vegetable oils2003-08-11 Issued
2004-01-01Implementation
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
GB/T 5009.176--2003bzxz.net
This standard is issued by the Ministry of Health of the People's Republic of China and is under the jurisdiction of the provincial health prevention and control station; participating units: Chemical Engineering Department of Fujian Normal University, Cotton and Tea Quality Inspection Center
The main drafters of this standard: Daohui, Guoyue, Lin Waiqing, Wa Jinming, Zhang Dai 441
GB/I ​​5009.175-2003
Dicfnl is a low-oxygen sterilizing alcohol that has been approved for use on tea, apples, pears and cotton in my country. Because some dicfnl are not of high purity and contain impurities, they are prohibited from being used on tea trees. The national standard stipulates that the residue limit of trichloroacetol in citrus fruits is 5 mg/kg, the residue limit in cotton is 1.1 mg/kg, and the residue limit in tea is 1.1 mg/kg. This standard provides a method for determining the residue of trichloroacetol as a complementary determination method to the above residue limit national standards. 43
Determination of trichloroacetol residues in tea, fruit and edible vegetable oils
This standard specifies the method for determining the residue of trichloroacetol in tea, fruit and edible vegetable oils. This standard uses the determination of trichloroacetol in tea, fruit and edible vegetable oils. GB/15009,176—2003
The detection range of this method is 8.0×101g: Step 1 For fruits, the amount of benzene leaf test orange is 5.0 and the fixed volume is 10L. The minimum detection concentration of this method is 1.6×10-mg/kg. The lower limit of determination is 9.6x15-mR/kg. When the oil sample volume is 1.ug and the fixed volume is mL, the minimum detection concentration of this method is 1.ex11m/hk-the lower limit of determination is %.6×10-mg/kg: The amount of this method will be .ox20-1ng~l.ng. 2 Principle
The first three chlorotea mite ferments are extracted in the test column, and the extract is purified with acid at the same time as the standard series, and then with an electric The gas chromatograph of the oil ash detector is used for determination. The retention time of the color peak is used for qualitative determination and the content is determined by comparison with the standard. 3 Reagents
3.1 Add.
3.2 Petroleum ether: boiling range 30°C~G.
3.3 Acetone
3.4 ​​Sulfuric acid (GR).
3.5 Anhydrous sodium thiosulfate: 651 calcined for 1h. Set aside in the flask for use: 3.6 Sodium sulfate solution, 2Cg/L.
3.7: chloranil ion solution: accurately weigh (accuracy, 0.01g) and distill at the end of the second stage. Alcohol standard (Shanyuol. Jidu 05) is prepared with leather to make 1n0.0g/mL standard energy reserve. 3.8 Trioxygen alcohol standard use reduction, the above standard reserve is reduced by petroleum energy to the appropriate concentration, generally .C5pg/mL. 200r4g/mL. 4 Instruments and equipment
4.1 Gas chromatograph with electric discharge detection terminal (ECD).
4.2 Small paste crusher.
4.3 Tissue crusher.
4.1 Coarse scrubber,
4.5 Sensing machine: 4(o0 T/ mm.
5 Analysis steps
5.1 Pretreatment
5.1.1 Water: Weigh about 200g of cracked or apple fruit samples, crush them in a crusher, and mix them. Take about 5g of the pulp (accurate to 0.61g), put it in a 5mL conical flask, add 10ml~151ml acetone, vibrate for 5min, filter it in 125mL separatory water, wash it 4 times with a little acetone, and wash the filter with 3% sodium pyrolysis ether for 1min. Add 20ml sodium pyrolysis solution (20g/L). Let it stand for 1min. Let it stand for 1 minute and let the layers separate. Discard the lower layer of water, drain the water inside and outside the separatory flask, then drain the water, filter it, and add 10% anhydrous sodium pyrolysis tongs into a 50mL bottle. Divide the mixture into 3 portions with a small amount of sodium sulfate, drain and mix, add the washing liquid into the filtrate, dilute the sodium sulfate, transfer to a 143 mL test tube and make up to 0.5 g of the sample (mixed to 0.1 g), add 20 mL sodium sulfate to a 135 mL tube, add 30 mL sodium sulfate to a supernatant, add 50 mL sodium sulfate to a colorimetric disk, and add 15 mL sodium sulfate to the filtrate. Add the washing liquid into the colorimetric disk, and finally add sodium sulfate to make up to 10. CL: 5.1.3 Take 1.0% of the representative uniform edible sample and dissolve it in 1.0% sodium carbonate solution in a tube, adjust to 1.3 mL
5. 2%
Pipette the extracted solution into a -0 mL colorimetric medium, add 1.5 L sulfuric acid, and cover with a trachea cord. After vibrating several times, open the chamber and change the air: then simmer for 1 minute, 3 1 6001mi high-speed centrifuge 1=mit, the supernatant was absorbed and the sample was concentrated to 1.3)mT.> for gas chromatography-mass spectrometry: 5.3 Standard curve preparation
Preparation of a chlorinated alcohol standard series 0.0.0 yuan. 0.: 30.26.3.500, 75.1.00g/ml. Take 5.9mL of each test: add 1,:mr concentrated acid, hold 1min, centrifuge at 1600 r/mi for 15min, and then the supernatant was added to another group of samples for colorimetric selection, and the injection was 1.
5.4 Residue determination
5.4.1 Chromatographic analysis
Absorb the purified chlorinated alcohol standard and use the reduced sample purification solution! . Enter the column, respectively five times, qualitatively, and quantitatively by comparing the peak area of ​​the drug sample with that of the standard. Under the above chromatographic conditions, the conformal time of trichlorfon is 6.9ri11. 5.4.2 Recommended gas chromatography conditions
Chromatographic column: 13-1 type fine column, 0m×0,25:mm inner diameter). Chromatographic temperature: 24u% inlet single 11 wet waste, 260; detector temperature: 300°. Gas N. density. 99%. Flow rate. CL/mia..50 kPa. Split ratio. 0.5.4.3 Gas chromatogram Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 29 Figure 29 Figure 20 Figure 21 Figure 29 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 29 Figure 29 Figure 29 Figure 29 Figure 20 ... The unit is gram per dry mass (mg/kg); A—sample surface area:
c…. Standard sample mass concentration, unit is gram per liter (mI).); A, standard sample peak area:
V.·Sample injection volume, unit is microliter (pi); —sample standard volume, unit is liter (mI>+sample sample volume. Unit is microliter (uL); sample mass, unit is gram (R).
7 Density
GB/ 5009, 176—2003
The absolute difference of two independent determination results obtained under repeatability test shall not exceed 1% of the arithmetic mean.
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