GB/T 44243-2024 PDF EnglishUS$500.00 · In stock · Download in 9 seconds
GB/T 44243-2024: Hydrogen for proton exchange membrane fuel cell vehicles - Determination of sulfur compounds, formaldehyde and organic halides - Gas chromatography method Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid
Similar standardsGB/T 44243-2024: Hydrogen for proton exchange membrane fuel cell vehicles - Determination of sulfur compounds, formaldehyde and organic halides - Gas chromatography method---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/GBT44243-2024 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 27.010 CCS F 19 Hydrogen for proton exchange membrane fuel cell vehicles - Determination of sulfur compounds, formaldehyde and organic halides - Gas chromatography method Issued on: JULY 24, 2024 Implemented on: NOVEMBER 01, 2024 Issued by. State Administration for Market Regulation; Standardization Administration of the People’s Republic of China. Table of ContentsForeword... 4 1 Scope... 5 2 Normative references... 5 3 Terms and definitions... 6 4 Principle... 6 5 Reagents and materials... 6 5.1 Gas... 6 5.2 Gas reference materials... 7 6 Instruments and equipment... 7 6.1 System... 7 6.2 Gas concentrator... 8 6.3 Gas chromatograph... 8 6.4 Gas diluter... 9 6.5 Sampling gas cylinder... 9 7 System performance verification... 10 7.1 General... 10 7.2 Sulfur chemiluminescence detector (SCD) verification... 10 7.3 Mass spectrometry detector (MSD) verification... 10 8 Test procedures... 11 8.1 Sampling... 11 8.2 Operating conditions... 11 8.3 Preparation... 11 8.4 Sample introduction... 11 8.5 Sample pre-determination... 11 8.6 Calibration... 11 8.7 Blank determination... 13 8.8 Sample determination... 13 9 Test data processing... 13 9.1 Qualitative analysis... 13 9.2 Quantitative analysis... 14 9.3 Total sulfur... 15 9.4 Total organic halides... 15 9.5 Non-target compounds... 15 9.6 Expression of results... 15 10 Precision and accuracy... 15 10.1 Precision... 15 Hydrogen for proton exchange membrane fuel cell vehicles - Determination of sulfur compounds, formaldehyde and organic halides - Gas chromatography method Warning. Hydrogen is a flammable and explosive gas. This document does not purport to address all of the safety concerns associated with its application. Before using this document, the user is responsible for formulating appropriate safety and protection measures, clarifying its limited scope of application, and ensuring compliance with relevant national laws and regulations and mandatory national standards.1 ScopeThis document describes the principle, reagents and materials, instruments and equipment, system performance verification, test procedures, test data processing, precision and accuracy, quality assurance and control, and test report for the determination of sulfur compounds, formaldehyde and organic halides in hydrogen for proton exchange membrane fuel cell vehicles using the pre-concentration-gas chromatography-sulfur chemiluminescence detector/mass spectrometry detector method. This document applies to the determination of sulfur compounds, formaldehyde and organic halides in hydrogen for proton exchange membrane fuel cell vehicles; it serves as a reference for the determination of sulfur compounds, formaldehyde and organic halides in hydrogen for other purposes within the range specified in this document. The determination range of sulfur compounds in this document is 0.10 nmol/mol ~ 10.0 nmol/mol, and the detection limit of hydrogen sulfide is 0.01 nmol/mol. The determination range of formaldehyde is 1.0 nmol/mol ~ 400.0 nmol/mol, and the detection limit is 0.1 nmol/mol. The determination range of organic halides is 1.0 nmol/mol ~ 100.0 nmol/mol, and the detection limit of methyl chloride is 0.5 nmol/mol.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document. GB/T 43306, Gas analysis - Sampling guidelines GB/T 44262, Technical requirements for sampling of hydrogen for proton exchange membrane fuel cell vehicles JJF 1342, General Requirements for the Competence of Reference Material Producers3 Terms and definitionsNo terms and definitions need to be defined in this document.4 PrinciplePass the sample into a gas concentrator to capture and desorb the target compound. Introduce the desorbed sample into a gas chromatograph equipped with a non-polar capillary column. The components to be tested separated by the column pass through a splitter assembly, one path enters a sulfur chemiluminescence detector for sulfur compound detection, and the other path enters a mass spectrometer for formaldehyde and organic halide detection. Use the external standard method for quantification.5 Reagents and materials5.1 Gas 5.1.1 Carrier gas. helium, with a purity of not less than 99.999%. Desulfurization traps as well as dehydration, dehydrocarbonization and deoxygenation filters shall be installed; the concentration of sulfur compounds in the purified gas shall not interfere with sample detection. 5.1.2 Fuel gas. hydrogen, with a purity of not less than 99.999%. Desulfurization traps as well as dehydration and dehydrocarbonization filters shall be installed; the concentration of sulfur compounds in the purified gas shall not interfere with sample detection. 5.1.3 Gas for ozone generator. oxygen, with a purity of not less than 99.999%. Desulfurization traps as well as dehydration and dehydrocarbonization filters shall be installed; the concentration of sulfur compounds in the purified gas shall not interfere with sample detection. 5.1.4 Combustion-supporting gas. air, dry air that meets the requirements for use of gas chromatograph. An air generator with a purifier can be used. Desulfurization traps as well as dehydration and dehydrocarbonization filters shall be installed; the concentration of sulfur compounds in the purified gas shall not interfere with sample detection. 5.1.5 Liquid nitrogen. used as the refrigerant in liquid nitrogen refrigeration concentrators. 5.2 Gas reference materials 5.2.1 The qualifications of institutions for gas reference material production (development) shall comply with the requirements of JJF 1342.Users shall give priority to certified gas reference materials. 5.2.2 The mixed reference materials of sulfur compounds should contain the following components. hydrogen sulfide, carbonyl sulfide, ethyl mercaptan, dimethyl sulfide, carbon disulfide, thiophene, dimethyl disulfide; the balance gas shall be nitrogen, helium or hydrogen; the preparation scheme can also be designed according to needs. For newly purchased gas reference materials, their standard values should be confirmed according to 7.2.2. 5.2.3 The mixed reference materials of organic halides should contain the following components. methane chloride, dichloromethane, trichloromethane, dichloroethylene, tetrachloroethylene, chlorobenzene, trichlorofluoromethane, methyl bromide; the balance gas shall be nitrogen, helium or hydrogen; the preparation scheme can also be designed according to the needs. 5.2.4 The balance gas for formaldehyde reference material should be nitrogen or helium. 5.2.5 Based on the preparation quality of various target compounds by the gas reference material production (research and development) organization, it is advisable to purchase gas reference materials with target values as close as possible to the technical indicator limits of sulfur compounds, formaldehyde and organic halides required by GB/T 37244 or other hydrogen uses. For example, the preparation target value of each component can be set at 1.00×10-6 mol/mol.6 Instruments and equipment6.1 System The system consists of a gas concentrator, and a gas chromatograph equipped with a sulfur chemiluminescence detector and a mass spectrometer. The recommended system configuration diagram is shown in Figure 1.The system can also be composed of a gas chromatograph equipped with a sulfur chemiluminescence detector AND a gas chromatography-mass spectrometer. Use a capillary column coated with 100% dimethylpolysiloxane on the inner wall or other equivalent column. 6.3.2 Sulfur chemiluminescence detector (SCD) For the detection of the form and content of sulfur compounds, the technical indicators of the sulfur chemiluminescence detector shall at least meet the following requirements. -- The linear range is greater than 104; -- The minimum detection amount of sulfur is less than 0.5 pg/s; -- The selectivity of sulfur compounds to hydrocarbon compounds is greater than 106. 6.3.3 Mass spectrometry detector (MSD) For the detection of formaldehyde and organic halides, the technical indicators of the mass spectrometry detector shall at least meet the following requirements. -- Equipped with electron bombardment ion source (EI), with ionization energy 70 eV; -- Provided with full scan (SCAN) and selected ion monitoring (SIM) modes; -- Full scan range. m/z = 28 ~ 200. 6.4 Gas diluter 6.4.1 A gas diluter that complies with the provisions of GB/T 5275.6 should be used. The materials in contact with the sample gas, such as gas lines and pipe joints, shall be made inert. 6.4.2 The dilution ratio should range from 2 ~ 2000 times, and the relative deviation of the dilution ratio shall not exceed ±2%. 6.4.3 The diluent gas may be nitrogen, helium or hydrogen. Nitrogen or helium, with a purity of not less than 99.999% and without containing the target component to be measured, should be used. 6.4.4 The diluter shall have automatic or manual flow calibration function for different types of dilution gases. 6.4.5 The gas diluter shall be calibrated regularly by a qualified metrology agency. 6.5 Sampling gas cylinder The sampling gas cylinder shall comply with the requirements of GB/T 44262 and GB/T 43306.7 System performance verification7.1 General System performance shall be evaluated and analyzed regularly to ensure reliable operation of the system. System performance shall also be evaluated and analyzed when the method is initially established, when the machine is restarted, when instruments and equipment are repaired and maintained, when operating conditions are changed, and when new gas reference materials are purchased. 7.2 Sulfur chemiluminescence detector (SCD) verification 7.2.1 Linear dependence Test 5 ~ 7 calibration samples of sulfur compounds with different content levels within the measurement range; establish a component content and peak area calibration curve model that is forced to pass through the origin based on the least squares method. The calibration curve shall be linear, and R2 shall be no less than 0.99.During routine use, verification is required when the interval between sample analyses exceeds 7 days. 7.2.2 Equimolar response The SCD response is proportional to the mass of sulfur. The relative deviation of the response factor of each component in terms of sulfur shall be within 30% of the response factor of carbonyl sulfide or dimethyl sulfide. During routine use, verification shall be performed every six months. 7.3 Mass spectrometry detector (MSD) verification Test 5 ~ 7 formaldehyde and organic halide calibration samples with different content levels within the measurement range; establish a calibration curve model of component content and peak area forced to pass through the origin based on the least squares method. The calibration curve shall be linear, and R2 shall be no less than 0.99.During routine use, verification shall be performed once a month. Note. Deviations in different dilution ratios of the diluter, deviations in volumetric measurement of the concentrator, adsorption effects of the concentrator on sulfur compounds, reductions in capture and desorption efficiency of the concentrator, chromatographic column failure, and SCD burner failure may all lead to validation failures.8 Test procedures8.1 Sampling The sampling of hydrogen for proton exchange membrane fuel cells shall comply with the provisions of GB/T 44262. 8.2 Operating conditions Typical operating conditions of gas concentrators with different working principles are shown in Tables A.1, A.2 and A.3 in Appendix A. Typical gas chromatographic parameters and operating conditions are shown in Table B.1 in Appendix B. 8.3 Preparation After the gas chromatograph is turned on, it is allowed to stabilize under the set operating conditions for about 8 hours until the SCD and MSD baselines are stable and the SCD burner pressure and temperature values meet normal use requirements. 8.4 Sample introduction Use an inertized pressure reducing valve and inertized stainless steel tubing to introduce the sample into the concentrator inlet. 8.5 Sample pre-determination 8.5.1 Test the samples using the established operating conditions. Estimate the target compound content based on the results of the most recent calibration test. 8.5.2 When the estimated content is higher than the lowest value in the calibration series, calibrate according to 8.6.1 or 8.6.2. 8.5.3 When the estimated content is between the lower limit of the target compound's measurement range and the method detection limit, calibrate according to 8.6.2. 8.5.4 When the target compound is not detected in the sample, perform the test according to 8.6.3. 8.6 Calibration 8.6.1 Multi-point calibration 8.6.1.1 Calibration sample preparation Prepare calibration samples with different concentrations of each target compound according to Table 1. Ax (i) – peak area of the target compound x at the ith calibration point; φx (i) – content of the target compound x at the ith calibration point, in nanomoles per mole (nmol/mol). Note. The chromatographic peak area of sulfur compounds is obtained using SCD. The characteristic ion peak areas of formaldehyde and organic halides are obtained using MSD. Tables B.2 and B.3 in Appendix B give the corresponding characteristic ions. 8.6.2 Single-point calibration For systems that have passed the verification test within 7 days and are in stable operating condition, single-point calibration can be performed using Formula (2), with the value of n being 1.The target value of the calibration point shall be close to the estimated content of the sample. 8.6.3 Processing of samples with undetected components Refer to Appendix D to prepare samples with the detection limit of the target compound method and conduct the test. The chromatographic peak of the target compound shall be clearly identifiable in the chromatogram, and the signal-to-noise ratio of 90% of the components shall be greater than 2. 8.7 Blank determination Before sample testing, use hydrogen or helium to purge the system, and carry out a blank test under the same test conditions, ensuring that the content of the residual components is lower than the detection limit of the method and avoiding interference with the sample determination. 8.8 Sample determination Use the same test conditions as the calibration samples; measure each sample twice, between which the relative deviation of the peak area of each component shall be within 10%. Record the mean peak area of each component. Sample testing should be completed within 3 days after collection. The storage of samples should be carried out in accordance with the provisions of GB/T 34525.9 Test data processing9.1 Qualitative analysis 9.1.1 Perform the qualitative analysis of sulfur compounds by comparing the retention time of each component with that of the reference material. See Figure B.1 in Appendix B for the typical chromatogram. φs – content of standard point s, in nanomoles per mole (nmol/mol); As – peak area of the calibration point s. 9.3 Total sulfur The total sulfur content expressed as mole fraction is the sum of the contents of all known and unknown individual sulfur compounds. The content of unknown sulfur compounds is calculated using the quantitative parameters of dimethyl sulfide. 9.4 Total organic halides The total organic halide content, expressed as mole fraction, is the sum of the contents of all individual organic halides. For organic halides not included in the list of reference materials, the quantitative parameters of components of the same type can be used for calculation. 9.5 Non-target compounds Use formaldehyde or methyl chloride of the known content as the quantitative parameter to estimate the non-target compounds. For its accurate quantification, it’s necessary to prepare a calibration sample based on the estimated values, and then perform analysis and calculation. 9.6 Expression of results The measurement results should be expressed as follows. -- When the measured value is not less than 1 nmol/mol, round to one decimal place. -- When the measured value is less than 1 nmol/mol, round to two decimal places. -- For samples of undetected components that pass the detection limit confirmation test in Appendix D, express the results for sulfur compounds as "< 0.01 nmol/mol", the results for formaldehyde as "< 0.1 nmol/mol", and the results for organic halides as "< 0.5 nmol/mol". -- For samples of undetected components that fail the detection limit confirmation test in Appendix D, express the results as less than the lower limit of the method's measurement range, or less than the detection limit data obtained through actual testing.10 Precision and accuracy10.1 Precision 10.1.1 Precision overviewAppendix C(Informative) Examples of preparation methods for calibration samples at different concentration levels C.1 Preparation principle The laboratory shall select an appropriate method for preparing calibration samples of target compounds according to the calibration range of the target compounds, the optimal dilution ratio range of the diluter, and the optimal sampling volume of the concentrator, referring to C.2 ~ C.4. C.2 Example of preparation methods with different dilution ratios and different concentration volumes Example. Prepare calibration samples of sulfur compounds of seven content levels listed in Table 1. Dilute the mixed sulfur compound gas reference material with a standard value of 1.00×10-6 mol/mol 100 times to 10.0 nmol/mol; set the base sampling volume of the concentrator to 500 mL; set the sampling volumes in the concentrator control procedure to 500 mL, 200 mL and 100 mL respectively; measure in sequence according to 9.1 to obtain test data of sulfur compounds with contents equivalent to 10.0 nmol/mol, 4.0 nmol/mol and 2.0 nmol/mol; then, dilute the gas reference material with a standard value of 1.00×10-6 mol/mol 1 000 times to 1.0 nmol/mol; set the sampling volumes in the concentrator control procedure to 500 mL, 250 mL, 100 mL and 50 mL respectively; measure in sequence to obtain test data with contents equivalent to sulfur compounds of 1.0 nmol/mol, 0.50 nmol/mol, 0.20 nmol/mol and 0.10 nmol/mol. C.3 Example of preparation methods with fixed dilution ratio and different concentration volumes Example. Prepare calibration samples of organic halides of seven content levels listed in Table 1. Dilute the mixed organic halide gas reference material with a standard value of 1.00×10- 6 mol/mol by 10 times to 100 nmol/mol; set the base sampling volume of the concentrator to 800 mL; set the sampling volumes in the concentrator control procedure to 800 mL, 400 mL, 160 mL, 80 mL, 64 mL, 40 mL and 8 mL; measure in sequence according to 9.1 to obtain test data for 7 calibration samples with contents equivalent to organic halides of 100.0 nmol/mol, 50.0 nmol/mol, 20.0 nmol/mol, 10.0 nmol/mol, 8.0 nmol/mol, 5.0 nmol/mol and 1.0 nmol/mol. ......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 44243-2024 be delivered?Answer: The full copy PDF of English version of GB/T 44243-2024 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 44243-2024_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 44243-2024_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 44243-2024 -- 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 44243-2024?A step-by-step guide to download PDF of GB/T 44243-2024_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 44243-2024". 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 |
