GB/T 21728-2008 English PDF

US$139.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email.
GB/T 21728-2008: Determination of fluoride content n brick tea
Status: Valid

Standard ID	USD	BUY PDF	Lead-Days	Standard Title (Description)	Status
GB/T 21728-2008	139	Add to Cart	3 days	Determination of fluoride content n brick tea	Valid

Similar standards

GB/T 21918   GB/T 21727   GB/T 21311   GB/T 15683   GB/T 21719   

Basic data

Standard ID: GB/T 21728-2008 (GB/T21728-2008)
Description (Translated English): Determination of fluoride content n brick tea
Sector / Industry: National Standard (Recommended)
Classification of Chinese Standard: X04
Classification of International Standard: 67.140.10
Word Count Estimation: 6,655
Date of Issue: 2008-05-04
Date of Implementation: 2008-10-01
Quoted Standard: GB/T 8302; GB/T 8303
Regulation (derived from): National Standard Approval Announcement 2008 No.6 (Total No.119)
Issuing agency(ies): General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China
Summary: This standard specifies the use of ion-selective electrodes detect brick fluoride content approach. This standard applies to brick fluorine content of the finished product and raw material testing.

GB/T 21728-2008: Determination of fluoride content n brick tea

---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.
Determination of fluoride content n brick tea ICS 67.140.10 X04 National Standards of People's Republic of China Detection brick tea fluoride content Posted 2008-05-04 2008-10-01 implementation Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China Standardization Administration of China released

Foreword

This standard is proposed and managed by China Federation of Supply and Marketing Cooperatives. This standard was drafted. China Federation of Supply and Marketing Cooperatives Hangzhou Tea Research Institute. The main drafters of this standard. Zhou Weilong, Xu Jianfeng, Weng Kun. Detection brick tea fluoride content

1 Scope

This standard specifies the ion selective electrode detection method of brick tea fluoride content. This standard applies to raw materials and finished brick fluorine content test.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard. GB/T 8302 sampling tea Sample Preparation and Determination of dry matter content GB/T 8303 Tea grated

3 Terms and Definitions

The following terms and definitions apply to this standard. 3.1 Including black tea, Fu brick tea, flower tea, brick tea, Kang brick tea, rice tea, golden tip tea, tea tight, Tuocha like. Principle 4 FISE lanthanum fluoride single-crystal film of the fluoride ion selective response to produce the number of fluorine electrode and a saturated calomel electrode in the test Test solution, the potential difference can change with the solution of fluorine ion activity changes, variation in line with the Nernst potential (Nernst) equation, See equation (1). E = E0-2.303RTF lg Ba F - (1) Where. E --- electromotive force, in millivolts (mV); E0 --- under certain experimental conditions constant value, in millivolts (mV); R --- molar gas constant, 8.31441J/(mol · K); T --- thermodynamic temperature, the unit is open (K); F --- Faraday constant, 96486.70C/mol; ---- F. Ba fluoride ion concentration in units of moles per liter (mol/L). E and lg Ba F- linear. 2.303RT/F for the slope of the line (25 ℃ when 59.16). Fluoride ion forms a complex with the Fe3 +, Al3 + and SiO32- plasma interfere with the determination of other common ions had no effect, the acidity of the liquid is measured pH5 ~ 6, the total ionic strength adjustment Festival buffer eliminate interfering ions and its acidity.

5 Instruments

5.1 fluorine electrode. PF-1 type or other models. 5.2 pH meter. pHS-2 type or potentiometer. 5.3 magnetic stirrer. ......

Image     

Tips & Frequently Asked Questions:

Question 1: How long will the true-PDF of GB/T 21728-2008_English be delivered?

Answer: Upon your order, we will start to translate GB/T 21728-2008_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/T 21728-2008_English with my colleagues?

Answer: Yes. The purchased PDF of GB/T 21728-2008_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.

Question 3: Does the price include tax/VAT?

Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countries

Question 4: Do you accept my currency other than USD?

Answer: Yes. If you need your currency to be printed on the invoice, please write an email to Sales@ChineseStandard.net. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.