GB 23200.16-2016 English PDFUS$179.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. GB 23200.16-2016: Food safety national standard -- Determination of ethephon residues in fruits and vegetables -- Liquid chromatographic method Status: Valid
Basic dataStandard ID: GB 23200.16-2016 (GB23200.16-2016)Description (Translated English): Food safety national standard -- Determination of ethephon residues in fruits and vegetables -- Liquid chromatographic method Sector / Industry: National Standard Classification of Chinese Standard: G25 Word Count Estimation: 9,912 Date of Issue: 2016-12-18 Date of Implementation: 2017-06-18 Older Standard (superseded by this standard): NY/T 1016-2006 Regulation (derived from): State Health Commission, Ministry of Agriculture, Food and Drug Administration Notice No. 16 of 2016 Issuing agency(ies): National Health and Family Planning Commission of the People's Republic of China, State Food and Drug Administration GB 23200.16-2016: Food safety national standard -- Determination of ethephon residues in fruits and vegetables -- Liquid chromatographic method---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. Food safety national standard - Determination of ethephon residues in fruits and vegetables - Liquid chromatographic method National Standards of People's Republic of China GB Instead of NY/T 1016-2006 National standards for food safety Determination of ethephon residues in fruits and vegetables Gas chromatography National food safety standards- Determination of ethephon residue in fruits and vegetables Gas chromatography 2016-12-18 Release.2017-06-18 Implementation National Health and Family Planning Commission of the People 's Republic of China Issued by the Ministry of Agriculture of the People 's Republic of China State Administration of Food and Drug Administration ForewordThis standard replaces NY/T 1016-2006 "Determination of ethephon residues in vegetables by gas chromatography". This standard and GB/T 5009.7-2008 compared to the main changes are as follows. - modified in accordance with the format of food safety standards; - normative reference documents to increase the GB 2763 "maximum pesticide residues in food" standard; - the preparation of the sample to increase the sampling site requirements and refine the requirements of the preparation of the sample; - Increased precision requirements. National standards for food safety Determination of ethephon residues in fruits and vegetables - Gas chromatographic method1 ScopeThis standard specifies the determination of ethephon residues in fruits and vegetables. This standard is applicable to the analysis of ethephon residues in fruits and vegetables.2 normative reference documentsThe following documents are indispensable for the application of this document. For dated filing applications, only the dated edition applies to this document. For undated references, the latest edition (including all modifications) applies to this document. GB 2763 National Standard for Food Safety - Maximum Residue Limit of Pesticides in Foodstuffs GB/T 6682 Analytical laboratory water specifications and test methods3 principleExtraction of ethephon from the sample with methanol and derivatization of dimethylethylenediethanoxide by diazomethane with a flame photometric detector (phosphor filter) The gas chromatograph was determined by external standard method.4 reagents and materialsUnless otherwise stated, only chromatographic pure reagents are used in the analysis, and water is the primary water specified in GB/T 6682. 4.1 Reagents 4.1.1 Potassium hydroxide (KOH). 4.1.2 Hydrochloric acid (HCl). 4.1.3 Methanol (CH3OH). 4.1.4 anhydrous ether (C2H6O). 4.2 solution preparation Methanol - hydrochloric acid solution (90 10). take 90mL of methanol added to 10mL hydrochloric acid, and mix. 4.3 standards Ethephon standard, purity ≥ 95%. 4.4 standard solution preparation 4.4.1 ethephon standard solution. accurately weighed the amount of ethephon standard, with methanol prepared into a mass concentration of 1000 mg/L standard storage Preparation of liquid. According to the need to dilute the standard stock solution with methanol to prepare the appropriate concentration of standard working fluid, the preparation process requires polyethylene containers. 4.4.2 Diazomethane solution. see Appendix A.5 instruments5.1 gas chromatograph and equipped with flame photometric detector. 5.2 Ultrasonic cleaner. 5.3 Tissue crusher. 5.4 nitrogen dryers.6 Analysis steps6.1 Preparation of the sample The samples of vegetables and fruit samples shall be sampled according to the provisions of Appendix A of GB 2763, and the whole sample shall be processed for the smaller samples. For a larger, substantially uniform sample, it can be divided or cut into small pieces on a symmetry or symmetry plane; for slender, flat or component Samples in different parts of the sample can be cut in different parts of small pieces or cut into small pieces or processing; take the sample after its chopped, fully mixed Uniform, with a quartile sampling or directly into the tissue crusher mashed into homogenate, into the polyethylene bottle in the -16 ℃ ~ -20 ℃ under the conditions of preservation. 6.2 Extraction Weigh the sample 10 g (accurate to 0.01g) in the polyethylene beaker, add 0.5 mL of methanol - hydrochloric acid solution and 50 mL of methanol, ultrasound Shock extraction 5min, filtered in 100 mL of polyethylene volumetric flask, the residue and then 30 mL of methanol extraction time, combined with the extraction of polyethylene Capacity bottle, the volume of 100 mL. 6.3 Derivatization Accurately absorb 10 mL of the above volume solution into the 15 mL polyethylene centrifuge tube, in a dry nitrogen flow on the 30 ℃ ~ 35 ℃ water bath Concentrated to about 1.5 mL, add 0.5 mL of methanol - hydrochloric acid solution and 8 mL of anhydrous ether, mixed well, placed 10 min, the supernatant Into another polyethylene centrifuge tube, the residual solution with 1 mL of anhydrous ether extraction 2 times, the extract into the above solution, at 30 ℃ ~ 35 ℃ Concentrate to about 1 mL in a water bath. In the fume hood, dropping the diazomethane solution into the concentrate until the yellow does not fade. Cover the claws, Placed for 15 min. Concentrated in a nitrogen stream at 30 ° C to 35 ° C to about 1 mL, diluted with ether to 2.00 mL, and analyzed by gas chromatography. 6.4 Derivation of standard solutions Take the appropriate amount of ethephon standard working solution (10.0 mL with methanol), follow the sample extraction and derivatization steps (5.2 and 5.3) To operate. 6.5 Gas Chromatographic Reference Conditions Column. FFAP 30 m x 0.32 mm (id) x 0.25 μm Elastic quartz capillary column or quite polar column. Carrier gas. nitrogen, flow rate 2.5 mL/min, purity ≥99.999%; Gas. hydrogen, flow rate 85 mL/min, purity ≥99.999%; Gas combustion. air, flow 110 mL/min. Inlet temperature. 240 ° C; Heating procedure. 120 ℃ (1min) 40 ℃/min230 ℃ (2min); Detector temperature 150 ° C. Detector. Flame photometric detector (phosphor filter). Injection volume. 1 μL. 6.6 Chromatographic analysis (5.3 and 5.4) of the standard sample and the sample to be tested, respectively, were injected into a chromatograph, The sample is compared with the peak area of the standard sample derivative and quantified by external standard method. 6.7 blank test The following steps (5.2 and 5.3) are carried out except for non-test samples.7 results calculatedThe residual amount of ethephon in the sample is calculated using a chromatographic data processor or according to formula (1) 1000ρ VmA VVA .. (1) Where. The residual amount of ethephon in the sample, in milligrams per kilogram (mg/kg); A chromatographic area of dimethylacetylene in sample solution; The peak area of dimethyl vinyl chloride in As - standard solution; The mass concentration of ethephon in the standard solution, in micrograms per milliliter (μg/mL); V-extraction solvent volume, in milliliters (mL); V1 - fractional volume in milliliters (mL); V2 - on the machine volume volume, in milliliters (mL); M-Weigh the quality of the sample in grams. The calculated results shall be deducted from the blank values and the calculated results shall be the arithmetic mean of the two independent determinations obtained under reproducible conditions Show that two valid digits are reserved.8 precisionThe ratio of the absolute difference between the two independent determinations obtained under reproducibility and its arithmetic mean (percentage) shall be in accordance with the Record B requirements. The ratio of the absolute difference between the two independent determinations obtained under reproducibility and its arithmetic mean (percentage) shall be in accordance with the Record C requirements.9 limit of quantificationThe limit of quantification for this standard method is 0.03 mg/kg. 10 Chromatogram Reference The chromatogram of ethephon at a concentration of 0.05 mg/L is shown in Fig.Appendix A(Normative appendix) Diazomethane Preparation of A1 2 - nitroso - 2 - methylurea In a 250 mL flask, add 13.5 g of methylamine hydrochloride, add 67 g of water, add 40.2 g of urine, slowly reflux for 2 h 45 min After vigorous reflux for 15 min, cooled to room temperature, 20.2 g of sodium nitrite was added and the solution was cooled to 0 ° C. 80 g of ice was added to a 1 L beaker, And cooled in an ice-salt bath, then 13.3 g of sulfuric acid was added and the methylurea-nitrite was just added with stirring so that the temperature did not exceed 0 ° C, about 1 h plus finished. Nitrosomethylurea into a crystalline foam floating on top, immediately by suction filtration and well dry, and then A small amount of ice water washing, the resulting crystal into a vacuum dryer drying, the temperature does not exceed 4 ℃. Preparation of A2 Diazomethane In a 500 mL round bottom flask, 60 mL of 50% sodium hydroxide solution and.200 mL of ether were placed and the mixture was cooled to 0 ° C and then shaken And 20.6 g of 2-nitrous acid-2-methylurea was added thereto, and the flask was charged with a condenser tube for distillation. The lower end of the condenser pipe is connected with a receiving pipe, Through a double-hole rubber stopper immersed in a 250 mL Erlenmeyer flask in 40 mL of ether, the conical flask was placed in an ice-salt bath to cool and release The resulting gas was passed through a second 40 mL of diethyl ether, which was similarly cooled to below 0 ° C, and the reaction flask was placed on a water bath at 50 ° C The boiling point of the ether, and shake from time to time, the distilled ether until the distillate color becomes colorless, usually 2/3 of the ether after distilling off Becomes colorless. The ether can not be evaporated in any case and the ether solution in the receiver is combined with 5.3 g to 5.9 g of diazomethane.Appendix B(Normative appendix) Laboratory repeatability requirements Table B.1 Laboratory repeatability requirements Measured component content Mg/kg Precision 0.001 36 > 0.01 > 1 14Appendix C(Normative appendix) Inter-laboratory reproducibility requirements Table C.1 Inter-laboratory reproducibility requirements Measured component content Mg/kg Precision 0.001 54 > 0.01 > 1 19 ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB 23200.16-2016_English be delivered?Answer: Upon your order, we will start to translate GB 23200.16-2016_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB 23200.16-2016_English with my colleagues?Answer: Yes. 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