GB/T 23769-2009 PDF English
US$130.00 · In stock · Download in 9 secondsGB/T 23769-2009: Inorganic Chemical Products - General Method for the Determination of pH Values Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedureStatus: Valid
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivery | Name of Chinese Standard | Status |
| GB/T 23769-2009 | English | 130 |
Add to Cart
|
0-9 seconds. Auto-delivery
|
Inorganic Chemical Products - General Method for the Determination of pH Values
| Valid |
Excerpted PDFs (Download full copy in 9 seconds upon purchase)PDF Preview: GB/T 23769-2009
GB/T 23769-2009: Inorganic Chemical Products - General Method for the Determination of pH Values---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/GBT23769-2009
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.060.01
G 10
GB 23769-2009
Inorganic Chemical Products - General
Method for the Determination of pH Values
Issued on. MAY 13, 2009
Implemented on. JANUARY 01, 2010
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of PRC.
Table of Contents
Foreword... 3
1 Scope... 4
2 Normative References... 4
3 Principle... 4
4 Safety Tips... 5
5 General Provisions... 5
6 Reagents... 5
7 Apparatus... 7
8 Analysis Procedures... 7
Appendix A (Informative) Precautions for Electrode Use... 9
Foreword
The Appendix A of this Standard is informative.
This Standard was proposed by China Petroleum and Chemical Industry Association.
This Standard shall be under the jurisdiction of National Inorganic Chemical
Subcommittee of National Technical Committee for Standardization of Chemistry
(SAC/TC 63/SC 1).
Chief drafting organizations of this Standard. Hubei Xingfa Chemicals Group Co., Ltd.;
CNOOC Tianjin Chemical Research & Design Institute; and Jiande Tianshi Calcium
Carbonate Co., Ltd.
Chief drafting staffs of this Standard. Li Xia, Zheng Guangming, Zhou Xinmin, and Xu
Rongzhu.
This Standard is first-time published.
Inorganic Chemical Products - General
Method for the Determination of pH Values
1 Scope
This Standard specifies the principles, safety tips, general provisions, reagents,
apparatus, and analytical procedures for the determination of the pH value of aqueous
solutions of inorganic chemical products by the potentiometric method.
This Standard is applicable to the determination of the pH value of aqueous solutions
of inorganic chemical products. The measurement range of pH value is 1~12.
2 Normative References
The provisions in following documents become the provisions of this Standard through
reference in this Standard. For dated references, the subsequent amendments
(excluding corrigendum) 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 6682-2008 Water for Analytical Laboratory Use – Specification and Test
Methods (ISO 3696.1987, MOD)
HG/T 3696.1 Inorganic Chemicals for Industrial Use - Preparations of Standard
and Reagent Solutions for Chemical Analysis - Part 1.Preparations of Standard
Volumetric Solutions
HG/T 3696.3 Inorganic Chemicals for Industrial Use - Preparations of Standard
and Reagent Solutions for Chemical Analysis - Part 3.Preparations of Reagent
Solutions
3 Principle
Immerse the specified indicator electrode and reference electrode or composite
electrode in the same test solution to form a primary cell whose electromotive force is
related to the pH value of the solution.
4 Safety Tips
Some reagents used in this standard are toxic or corrosive, so be careful when
operating! If splashed on the skin, rinse immediately with water; and seek medical
attention immediately if it is severe.
5 General Provisions
The standard buffer solution reagents used in this Standard refer to pH reference
reagents; other reagents and water refer to analytically-pure reagents and the Class-
III water specified in GB/T 6682-2008 unless other requirements are specified. Water
without carbon dioxide refers to carbon dioxide-free water as specified in HG/T 3696.3.
6 Reagents
6.1 Oxalate standard buffer solution.
Weigh 12.71g of potassium tetroxalate [KH3(C2O4)2 • 2H2O]; dissolve it in carbon
dioxide-free water; and dilute to 1000mL. The concentration of this solution c
[KH3(C2O4)2 • 2H2O] is 0.05mol/L.
6.4 Phosphate standard buffer solution.
Weigh 3.40g of potassium dihydrogen phosphate (KH2PO4) and 3.55g of disodium
hydrogen phosphate (Na2HPO4); dissolve them in carbon dioxide-free water; and dilute
to 1000mL. Potassium dihydrogen phosphate and disodium hydrogen phosphate shall
be dried in advance at 120°C±2°C for 2h. The concentration of this solution c (KH2PO4)
is 0.025 mol/L; and the concentration of this solution c(Na2HPO4) is 0.025 mol/L.
6.7 See Table 1 for the pH value of each standard buffer solution at different
temperatures.
The acidic pH standard buffer solution shall be stored in a hard glass or polyethylene
bottle; and is effective within three months. The alkaline pH standard buffer solution
shall be stored in a polyethylene bottle; and is effective within one month. When
turbidity, mildew or precipitation is found, it cannot be used any more.
7 Apparatus
7.1 Electrode (see Appendix A for the use of electrodes).
7.1.1 Indicator electrode. glass electrode;
7.2 Acidity meter. the graduation value is 0.02.
8 Analysis Procedures
8.1 Preparation of test solution
Prepare the sample into a test solution with certain concentration by the carbon
dioxide-free water according to the requirements of the product standard.
8.2 Calibration of acidity meter
Prepare two standard buffer solutions at the same time; so that the pH value of one
standard buffer solution is greater than and close to the pH value of the test solution,
and the other standard buffer solution is less than and close to the pH value of the test
solution. Calibrate the pH meter by the above two standard buffer solutions.
8.3 Determination
Rinse the electrode with water; then wash with the test solution; adjust the temperature
of the test solution to 25°C±1°C; and adjust the temperature compensation knob of the
acid meter to 25°C. Insert the electrode into the test solution; add a stir bar; under
stirring state (or according to the specific requirements of the product standard),
determine the pH value of the test solution; and the measured pH value shall be stable
for at least 1min.
Appendix A
(Informative)
Precautions for Electrode Use
A.1 Glass electrode
Soak the temporarily-unused glass electrodes in water, and change the water
frequently. The glass electrode that has not been used for a long period of time shall
be stored in a dry place; and it needs to be immersed in water for 24h in advance to
activate it before use.
When measuring the pH value, all the bulbs of the glass electrode shall be immersed
in the solution; and slightly higher than the ceramic core of the calomel electrode.
A.2 Calomel electrode
When calomel electrode is in use, the rubber plug of the small hole at the top of the
electrode shall be pulled out to prevent diffusion potential from affecting the test results.
There shall be no bubbles in the potassium chloride solution in the electrode to prevent
disconnection. A small amount of potassium chloride crystals shall be kept in the
solution to ensure the saturation of the potassium chloride solution; but the potassium
chloride crystals shall not be too much to prevent blocking the electrode and the
passage of the measured solution.
When potassium chloride solution or crystals are attached to the surface of the
electrode, it shall be rinsed with water at any time.
......
Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.
Tips & Frequently Asked QuestionsQuestion 1: How long will the true-PDF of English version of GB/T 23769-2009 be delivered?Answer: The full copy PDF of English version of GB/T 23769-2009 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 23769-2009_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 23769-2009_English will be deemed to be sold to your employer/organization who actually paid 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+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB/T 23769-2009 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds. How to buy and download a true PDF of English version of GB/T 23769-2009?A step-by-step guide to download PDF of GB/T 23769-2009_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).
Step 2: Search keyword "GB/T 23769-2009".
Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart.
Step 4: Select payment option (Via payment agents Stripe or PayPal).
Step 5: Customize Tax Invoice -- Fill up your email etc.
Step 6: Click "Checkout".
Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively.
Step 8: Optional -- Go to download PDF.
Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice.
See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9
|