GB/T 3208-2009 English PDFUS$229.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 3208-2009: Standard test method for the total sulfur content in benzene -- Type products by oxidative microcoulometry Status: Valid GB/T 3208: Historical versions
Basic dataStandard ID: GB/T 3208-2009 (GB/T3208-2009)Description (Translated English): Standard test method for the total sulfur content in benzene -- Type products by oxidative microcoulometry Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: G18 Classification of International Standard: 71.080.15 Word Count Estimation: 10,137 Date of Issue: 2009-07-08 Date of Implementation: 2010-04-01 Older Standard (superseded by this standard): GB/T 3208-1982 Quoted Standard: GB/T 1999; GB/T 8170 Adopted Standard: JIS K2541-2-2003, MOD Regulation (derived from): National Standard Approval Announcement 2009 No.9 (Total No.149) 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 principles of benzene products total sulfur content determination, test procedure, , reagents, instruments calculated results, precision and so on. This standard applies to coking benzene, determination coking coking toluene and xylene sulfur content. GB/T 3208-2009: Standard test method for the total sulfur content in benzene -- Type products by oxidative microcoulometry---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. Standard test method for the total sulfur content in benzene -- Type products by oxidative microcoulometry ICS 71.080.15 G18 National Standards of People's Republic of China Replacing GB/T 3208-1982 Microcoulometric method for determination of total sulfur content in benzene products Published on.2009-07-08 2010-04-01 Implementation General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Released by the Standardization Administration of China Microcoulometric method for determination of total sulfur content in benzene products Warning. In the test methods shown in this standard, some dangerous reagents and test instruments need to be used, and some operations also have certain risks. As it is not possible to specify all methods of safe use, it is the user's responsibility to adopt appropriate safety and health measures and to ensure The certificate complies with the conditions stipulated by the relevant laws and regulations of the state. 1 Scope1.1 This standard specifies the principles, reagents, equipment, test procedures, result calculation, precision, etc. for the determination of the total sulfur content of benzene products. 1.2 This standard applies to the determination of sulfur content in coking benzene, coking toluene and coking xylene. Measuring range. 1mg/kg～ 1000mg/kg. 1.3 For samples with nitrogen content exceeding 0.1% or chlorine content exceeding 1.0% per unit weight, there may be certain The error can be eliminated by adding an appropriate amount of sodium azide to the electrolyte of the titration vessel. This standard does not apply per unit weight Amounts of bromine and organometallic compounds content of more than 500mg/kg samples. 1.4 For samples with a sulfur content exceeding.200 mg/kg per unit weight, it can be diluted to about 50 mg/kg with isooctane or toluene. Re-measure.2 Normative referencesThe clauses in the following documents become clauses of this standard through reference in this standard. For dated references, all subsequent Amendments (excluding errata content) or revisions do not apply to this standard, however, parties to agreements based on this standard are encouraged to study Is the latest version of these files available. For undated references, the latest edition applies to this standard. GB/T 1999 Sampling method for coking oil products GB/T 8170 Numerical Rounding Rules and Representation and Judgment of Limit Values3 PrinciplesThe sample is mixed with oxygen in the combustion tube and burned, so that the sulfur in the sample is converted into sulfur dioxide, which is brought into the titration cell by the carrier gas. Dioxygen Sulfur reacts with I3- in the pool as follows. I3-+SO2+H2O→SO3+3I-+2H+ When I3- is consumed, the indicator-reference electrode pair indicates this change and sends the signal to the microcoulomb counter amplifier, which outputs A corresponding current is passed to the electrolytic anode-electrolytic cathode electrode pair, where the following reactions occur at the electrolytic anode. 3I-2e→I3- To supplement the I3- consumed by SO2, until the I3- produced by electrolysis restores the concentration of I3- in the titration cell to the concentration before the titration. Electrolysis produces The electricity consumed by I3- is the product of the digital display value of the microcoulomb counter and the selected electricity range. According to Faraday's law of electrolysis, through the standard sample Correction can calculate the sulfur content in the sample.4 Sample collection and preparationAccording to GB/T 1999 regulations.5 Reagents5.1 Reaction gas. oxygen, with a purity of not less than 99.99%. 5.2 Inert gas. argon or helium with a purity of not less than 99.99%. 5.3 Electrolyte. dissolve potassium iodide (KI) and sodium azide in 500 mL of distilled water according to the requirements in Table 1, and add glacial acetic acid. (CH3COOH), dilute the solution to 1000mL with distilled water. GB/T 3208-2009 6.1 Combustion furnace. The inlet, central and outlet parts of the combustion tube can be individually heated and adjusted. 6.2 Combustion tube. made of quartz, which can burn the sample in the atmosphere of oxygen and inert gas. 6.3 Titration cell. a glass electrolyte cell with a magnetic stirrer and a built-in indicator-reference electrode pair, which is used to test the cell The concentration of I3-; another electrolysis anode-electrolysis cathode electrode pair, its role is to maintain a constant concentration of I3-. The platinum sheet of the indicator electrode is semi-electric The reference electrode was a platinum wire half-cell in an I3-saturated electrolyte. The electrolytic anode is made of platinum sheet, and the electrolytic cathode is made of platinum wire. ginseng Both the specific electrode and the electrolytic cathode communicate with the central chamber of the titration cell through a bundle of glass capillaries. 6.4 Microcoulomb counter. It measures the potential of the indicator-reference electrode pair, compares this potential with a given bias voltage, and informs the difference. The signal is amplified to the corresponding current and then applied to the electrolytic anode-electrolytic cathode pair, so that the electrolysis produces I3-. 6.5 Sulfur content recorder. Provide a recorder for converting the electricity of the generating electrode into sulfur content. 6.6 Micro syringe. 10 μL, 20 μL, 50 μL, 100 μL. 6.7 Sample bolt. quartz or platinum material.7 Test steps7.1 Preparation of test equipment 7.1.1 Before carrying out the test, first confirm the combustion tube and gas duct as shown below. 7.1.1.1 Combustion tube. Check the combustion tube and quartz fiber for quartz aging and dirt, if not very clean, it needs to be cleaned Or perform a sufficient air-burning after replacement. 7.1.1.2 Gas duct. Check the gas duct for aging or dirt, and clean it sufficiently. 7.1.2 After cleaning the inside of the titration cell with the electrolyte, add the electrolyte to it until the electrodes are completely submerged. 7.1.3 Indicating electrode. connect the respective terminals of the reference electrode and the generating electrode to the circuit of the microcoulomb counter. Note. If a vertical test instrument is used, the end point potential needs to be set at this stage. 7.1.4 Connect the gas conduit of the titration cell to the top position of the outlet of the combustion tube, and energize the strip heater to make the gas conduit of the titration cell. The temperature is kept above 100°C. 7.1.5 Set the flow rate of oxygen and inert gas, the temperature of the combustion furnace, and the microcoulomb counter to meet the measurement conditions. Typical Conditions for Assays shown in Table 2. 7.2 Calibration 7.2.1 According to the range of sulfur content, select the appropriate sulfur standard solution or standard material. 7.2.2 Select the injection volume of the sulfur standard solution from Table 3, then use a micro-syringe to inject the sample, and inject the fuel according to the following method. Burn the tube. 7.2.2.1 When using the vertical instrument. insert the needle tip of the microinjector into the instrument through the sample filling port until it reaches the entrance of the combustion tube, then Then inject the sulfur standard solution into it at a speed of 1.0 μL/s ~ 1.2 μL/s, accurately read the injected amount or weigh its mass (accurate to 0.1 mg). 7.2.2.2 When using the horizontal instrument. insert the needle tip of the micro syringe into the test instrument through the sample filling port, and then insert the needle into the sample bolt. Sulfur standard solution was injected into it, and the injected amount was accurately read or its mass was weighed (accurate to 0.1 mg). Move the sample bolt to the entrance of the combustion tube, After holding for 20s to 60s, push it into the inlet of the combustion tube. Note. (1) In order to inject the sample at a certain speed, a blender or an automatic injector can be used. (2) Before and after injecting the sulfur standard solution, it is necessary to inhale the same volume of air into the micro syringe, and calculate the original injection volume of the solution according to the volume difference, so that Errors due to evaporation of the solution from the tip are avoided, ensuring accurate values can be obtained. (3) Failure to stop for a short time before pushing the specimen bolt into the inlet of the combustion tube will result in insufficient combustion of the specimen and failure to obtain the correct measured value. (4) If a horizontal instrument is used, the filling rate is 0.2 μL/s to 0.3 μL/s. 7.2.3 Check the shape of the sulfur peak. 7.2.3.1 The correct sulphur peak must be maintained (Figure 2B). 7.2.3.2 If the peak is tailed (Figure 2A), slightly increase the gain or perform bias control to keep the peak in the correct shape. GB/T 3208-2009 7.2.3.3 If the peaks appear sharp (Fig. 2C), reduce the gain slightly or perform bias control to keep the peaks in the correct shape. 7.2.4 Calculate the recovery coefficient according to the following formula (2). If the recovery factor is not within the range of 0.65 to 0.95, the test sample If there is a problem in itself, it is necessary to check the device parameters and re-prepare the sulfur standard solution and perform the measurement again. 7.2.5 Read and record the sulfur content value of the sulfur standard solution displayed on the sulfur content recorder. Repeat the operation three times to calculate the standard solution of each sulfur The average sulphur content of the liquid. 7.2.6 Using the sulfur mass (μg) and the average sulfur content value of each sulfur standard solution read by the sulfur content recorder, draw a diagram of each sulfur standard solution. liquid curve. When the sulfur content of the sample is similar to that of the sulfur standard, single-point calibration can be used, but the determination should be repeated at least three times. 7.2.7 Check the calibration line every day or every 10 samples to confirm whether the operating conditions have changed. 7.2.8 In order to confirm whether the test operation and the test equipment are normal, measure the sulfur standard solution (5.9) according to the sample measurement procedure, confirm and standardize it. value deviation. 7.2.8.1 When the test is carried out for the first time, the deviation between the test result and the standard value of the standard solution must be ensured within the calculation tolerance of formula (3). within the allowable error range. 7.2.8.2 When the first test is carried out, the deviation between the average value of the test results and the standard value of the standard solution must be ensured within Formula (4) is calculated within the allowable error range. GB/T 3208-2009 7.2.8.3 Confirm whether the test results are within the allowable error range. If it is not within the allowable error range, check the test instrument and repeat New test. 7.3 Determination of samples 7.3.1 For direct measurement. use a micro-syringe to draw an appropriate amount of sample, inject it into the combustion tube according to the operation in 7.2.2, and read the maximum surface area. accumulated value. Repeat the measurement twice and take the average value. Note. According to the estimated concentration of the sample, draw an appropriate amount of sample to make it roughly in the middle of the calibration line range. 7.3.2 When measuring by dilution. Weigh the sample correctly to the nearest 1 mg, dilute it to 50 mg/kg with isooctane or toluene, and obtain the test sample. required dilution of the sample solution. Determine the sulfur content of the diluted test solution according to the procedure of 7.3.1. Note. For samples whose sulfur content does not exceed.200mg/kg, direct measurement can be carried out, while for samples with sulfur content exceeding.200mg/kg, it is better to carry out Dilution assay.8 Result calculation8.1 When the sample is directly measured, read the sulfur content according to the calibration line, then calculate the sulfur content of the sample according to formula (5), and round it to the smallest value. Two digits after the point. 8.2 When the sample is diluted and measured, read the sulfur content according to the calibration line, and then calculate the sulfur content of the sample according to formula (6), round it to the smallest value. Two digits after the point. 8.3 Take the arithmetic mean of the results of the two parallel measurements as the measurement result. If the result of the second parallel determination exceeds the allowable error range, repeat the New test. 8.4 The rounding of numerical values shall be carried out in accordance with the provisions of GB/T 8170.9 PrecisionThe results of repeated tests and reproduction tests shall not exceed the allowable values specified in Table 4. ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 3208-2009_English be delivered?Answer: Upon your order, we will start to translate GB/T 3208-2009_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 3208-2009_English with my colleagues?Answer: Yes. 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