GB/T 8622-2006 PDF EnglishUS$125.00 · In stock · Download in 9 seconds
GB/T 8622-2006: Determination of urease activity in soya bean products for feeds Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid GB/T 8622: Historical versions
Similar standardsGB/T 8622-2006: Determination of urease activity in soya bean products for feeds---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT8622-2006GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 65.120 B 46 Replacing GB/T 8622-1988 Determination of urease activity in soya bean products for feeds Issued on. JUNE 09, 2006 Implemented on. SEPTEMBER 01, 2006 Issued by. General Administration of Quality Supervision, Inspection and Quarantine of PRC; Standardization Administration of PRC. Table of ContentsForeword... 3 1 Scope... 4 2 Normative references... 4 3 Terms and definitions... 4 4 Principles... 5 5 Instruments and equipment... 5 6 Reagents and solutions... 5 7 Preparation of specimens... 6 8 Measurement steps... 6 9 Calculation of results... 7ForewordThis standard is the revised edition of GB/T 8622-1988 "Determination of urease activity in soya bean products for feeds". The main differences between this standard and GB/T 8622-1988 are as follows. - CHANGE the consumption of phosphate in the urea buffer; - DEFINE the timing steps in the measurement process; - CHANGE the volume of distilled water, which is used to rinse the contents of the test tubes; - ADD the judgment of using the indicator as the end point; - ADD the number of reserved digits for the test results, setting to two decimal places. - INCREASE the allowable difference between two tests of samples ≤ 0.2 activity unit; the relative difference is ≤ 20%. This standard replace GB/T 8622-1988, from the date of implementation. This standard was proposed by AND shall be under the jurisdiction of the National Feed Industry Standardization Technical Committee. The responsible drafting organization of this standard. National Feed Quality Supervision and Inspection Center (Beijing). The main drafters of this standard. Ma Dongxia, Zuo Jiangwan, Fan Zhiying. This standard replaces the standard previously issued as follows. - GB/T 8622-1988. Determination of urease activity in soya bean products for feeds1 ScopeThis standard specifies the determination of urease activity in soybean products and their by-products. This standard applies to the determination of urease activity in soybeans, soybean products, and by-products. By this method, it can understand the degree of moist heat treatment of soybean products.2 Normative referencesThe provisions in following documents become the provisions of this Standard through reference in this Standard. For the dated references, the subsequent amendments (excluding corrections) or revisions do not apply to this Standard; however, parties who reach an agreement based on this Standard are encouraged to study if the latest versions of these documents are applicable. For undated references, the latest edition of the referenced document applies. GB/T 601 Chemical reagent - Preparations of standard volumetric solutions3 Terms and definitionsThe following terms and definitions apply to this standard. 3.1 Urease activity in soya bean products The mass of amino nitrogen, which is released by the decomposition of urea per minute per gram of soybean product, at 30 °C ± 0.5 °C and pH7.4 PrinciplesMix crushed soybean products with neutral urea buffer solution. Precisely incubate at 30 °C ± 0.5 °C for 30 minutes. Urease catalyzes the hydrolysis of urea, to produce ammonia.5 Instruments and equipment5.1 Pulverizer. There shall be no strong heat during pulverization. 5.2 Sample sieve. Pore size 200 μm. 5.6 Acidity meter. Accuracy 0.02, with magnetic stirrer and titration device. 5.7 Glass instruments commonly used in laboratories.6 Reagents and solutionsThe reagents are of analytical pure. The water shall meet the requirements of GB/T 6682. 6.1 Urea buffer solution (pH7.0 ± 0.1) Weigh 8.95 g of disodium hydrogen phosphate (Na2HPO4 • 12H2O). Dissolve 3.40 g of potassium dihydrogen phosphate (KH2PO4) in water. Dilute it to 1000 mL. Then dissolve 30 g of urea in this buffer solution. It is valid for 1 month. 6.2 Hydrochloric acid solution [c(HCl) = 0.1 mol/L] Pipette 8.3 mL of hydrochloric acid. Use water to dilute it to 1000 mL. 6.3 Sodium hydroxide solution [c(NaOH) = 0.1 mol/L] Weigh 4 g of sodium hydroxide. Dissolve it in water and dilute to 1000 mL. Prepare and calibrate it, according to the method specified in GB/T 601.7 Preparation of specimensUse a pulverizer (5.1), to pulverize a representative sample, so that it all passes through the sample sieve (5.2).8 Measurement stepsWeigh about 0.2 g of the prepared specimen (Chapter 7), accurate to 0.1 mg, into a glass test tube (if the activity is very high, it can weight 0.05 g of specimen). Add 10 mL of urea buffer (6.1). Immediately cover the test tube cap and shake vigorously.9 Calculation of results9.1 The urease activity X in soybean products is expressed in urease activity unit per gram (U/g), which is calculated according to formula (1). If the specimen is pre-dried before crushing, it can be calculated according to formula (2). 9.2 Repeatability. When the same analyst uses the same analytical method to make measurement, simultaneously or two consecutive times, the difference between the results is not more than 20% of the average value, if the activity is ≤ 0.2; the difference between the results is not more than 10% of the average value, if the activity is > 0.2. ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB/T 8622-2006 be delivered?Answer: The full copy PDF of English version of GB/T 8622-2006 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB/T 8622-2006_English with my colleagues?Answer: Yes. 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