Interpretation of GB/T 6052-2025: A Single Gas Chromatograph for the Determination of Critical Impurities in Carbon Dioxide

　　I. Standard Basic Information
　　Standard Number: GB/T 6052-2025
　　Standard Name: “Industrial Liquid Carbon Dioxide” Issuing Authority: State Administration for Market Regulation / National Standardization Management Committee
　　Effective Date: 2026-02-01

　　II. Which industries does the new national standard apply to?
　　GB/T 6052-2025 “Liquid Carbon Dioxide for Industrial Use” is primarily applicable to liquid carbon dioxide products intended for industrial applications. According to the standard’s explanatory notes, the industries to which it applies include:
　　Industrial gases; gas filling stations; welding and metalworking; metallurgy and casting; chemical production; refrigeration and dry ice; fire protection; oil and natural gas; water treatment and environmental protection; greenhouse agriculture, and more.
　　In the welding and metalworking industries, carbon dioxide is commonly used as a shielding gas in gas-shielded welding. If the gas contains excessive sulfides, hydrocarbons, carbon monoxide, moisture, or oxygen, it can compromise weld quality, leading to defects such as porosity, increased spatter, and cracking. Consequently, the new national standard imposes stricter quality‑control requirements for carbon dioxide used in welding, reflecting a significant step forward in industry‑wide quality improvement.
 

　　III. GB/T 6052-2025 specifies different requirements for carbon dioxide used in welding and non-welding applications.
　　The new national standard sets forth distinct technical requirements for carbon dioxide used in welding and for industrial carbon dioxide not intended for welding. The former includes a greater number of test items, whereas the latter has relatively fewer.
　　The technical requirements for industrial carbon dioxide intended for non-welding applications primarily include: moisture content; oil content; and odor.
　　However, for many gas‑related companies, even for non‑welding applications, end customers may still impose more stringent requirements. For instance, they may seek to quantify impurities such as total hydrocarbons, carbon monoxide, and total sulfur. Particularly in high‑end manufacturing, chemical reactions, and materials processing, the more rigorous the analytical capabilities, the greater the advantage in enhancing product competitiveness.

　　IV. Key Specification Requirements for Industrial Liquid Carbon Dioxide Used in Welding
　　According to the content of GB/T 6052-2025, carbon dioxide for welding is classified into different purity grades. Level, with the following key indicators:

　　V. The most significant change in the new national standard: shifting from conventional indicators to trace-level detection at the ppm level.
　　Following the implementation of GB/T 6052‑2025, particularly with respect to carbon dioxide for welding, enterprises must pay close attention to total sulfur, total hydrocarbons, and carbon monoxide. These parameters are no longer subject to simple routine physicochemical testing; instead, they require trace‑level analysis at the ppm level or even lower, using techniques such as gas chromatography. For gas filling stations and industrial gas manufacturers, this poses three practical challenges:
　　1. The existing detection configuration may no longer be sufficient.
　　If a laboratory is equipped only with an oxygen analyzer and a dew‑point/trace‑water analyzer, it can no longer fully meet the new national standard requirements for testing carbon dioxide used in welding.
　　2. Long turnaround times for outsourced testing hinder production efficiency.
　　If each batch of products must be sent out for testing, it not only results in long testing cycles and high costs but may also slow down the product release process. For filling stations and gas supply companies, testing efficiency directly impacts delivery efficiency.
　　3. Customer acceptance requirements will become increasingly stringent.
　　Welding, metalworking, and manufacturing companies are placing increasing emphasis on gas quality. When purchasing carbon dioxide, customers may not only require a certificate of compliance but also demand detailed test data for critical impurities. The company that first establishes robust testing capabilities will be better positioned to earn customer trust.

　　VI. Methodological Basis for Each Testing Item
　　6.1 Determination of Carbon Dioxide Content: Potassium Hydroxide Absorption Method
　　6.2 Determination of Oxygen Content: According to GB/T 6285 “Determination of Trace Oxygen in Gases—Electrochemical Method”
　　6.3 Determination of Total Sulfur Content: According to GB/T 28727, “Gas Analysis—Determination of Trace Sulfur Compounds in Gases—Flame Photometric Gas Chromatography.”
　　6.4 Determination of Water Content: In accordance with GB/T 5832.1-2016 “Gas Analysis — Determination of Trace Water Content — Part 1: Electrolytic Method” or GB/T 5832.2-2016 “Gas Analysis — Determination of Trace Water Content — Part 2: Dew Point Method.”
　　6.5 Determination of Total Hydrocarbon Content: GB/T 8984-2025 “Gas Analysis — Determination of Trace Levels of Carbon Monoxide, Carbon Dioxide, and Hydrocarbons in Gases — Flame Ionization Gas Chromatography”
　　6.6 Determination of Carbon Monoxide Content: GB/T 8984-2025 “Gas Analysis — Determination of Trace Levels of Carbon Monoxide, Carbon Dioxide, and Hydrocarbons in Gases — Flame Ionization Gas Chromatography”
　　6.7 Determination of phosphine content: Colorimetric method. (This test is applicable only to carbon dioxide produced as a by‑product from raw gas in phosphate mining processes.)
　　6.8 Determination of Oil Content: Visual Qualitative Method (Filter Paper Staining Method)
　　6.9 Determination of Odor: Olfactory Sensory Evaluation Method

　　VII. Recommended Solution: KR-GC2032-ICO2 – Dedicated Detection Solution for Industrial Liquid Carbon Dioxide
　　Before the new national standard was implemented, industrial‑grade carbon dioxide only needed to be tested for two parameters—oxygen and moisture. Following the adoption of GB/T 6052‑2025, many gas‑filling stations and industrial gas manufacturers have been required to add gas chromatography analysis for industrial‑grade CO₂, with detection limits now at the ppm level. However, the cost of a gas chromatograph is often quite high, posing a significant challenge for both upstream and downstream players in the industry.
　　In accordance with the testing requirements for industrial liquid carbon dioxide specified in GB/T 6052-2025, the KR‑GC2032‑ICO2 gas chromatography method for analyzing industrial liquid carbon dioxide is recommended.
　　This method is designed to address the characteristics of carbon dioxide samples and the requirements of the new national standard testing procedures, and can be used to determine total sulfur, total hydrocarbons, and carbon monoxide in carbon dioxide.
　　A single instrument can cover multiple key gas chromatography–based testing parameters specified in the new national standard, making it suitable for industrial gas producers, gas filling stations, carbon dioxide suppliers, and third-party testing laboratories.

　　VIII. KR-GC2032-ICO2 Scheme Configuration
　　The main configuration of this instrument is as follows:

　　This configuration fully takes into account the specific characteristics of carbon dioxide sample analysis:
　　Carbon dioxide samples pose a certain corrosive hazard.
　　Sulfide detection places stringent requirements on the inertness of piping and valve components.
　　Total hydrocarbon and carbon monoxide detection require high-sensitivity response.
　　Carbon monoxide detection typically requires conversion via a methane converter, followed by measurement with an FID.
　　Multi-valve, multi-column systems facilitate the separation and detection of different components.

　　9. Why is this approach suitable for the new national standard on industrial liquid carbon dioxide?
　　1. One instrument covers three key projects.
　　In GB/T 6052-2025, the newly added or strengthened key inspection items for carbon dioxide used in welding include: total sulfur; total hydrocarbons; and carbon monoxide.
　　The KR‑GC2032‑ICO2 can perform the aforementioned tests using a single instrument, eliminating the need for companies to procure multiple devices. For gas manufacturers and filling stations, this means:
　　Laboratory setup is simpler; equipment investment is more focused; operator training is more convenient; data management is more standardized; and post‑installation maintenance is more hassle‑free.
　　2. The detection limit is far below the national standard requirements, providing greater measurement confidence.

　　As can be seen, the detection limit of KR‑GC2032‑ICO2 is significantly lower than the limit specified in GB/T 6052‑2025. This is of great importance to users, because in quality control, it is not sufficient for an instrument to merely “just meet the standard limit”; rather, it should provide ample margin in sensitivity.
　　The greater the sensitivity margin, the more advantageous it is for:
　　Accurate identification of low‑level impurities; more rigorous pass/fail assessment; early warning of process variability; compliance with customers’ stringent internal control standards; readiness to meet future standard upgrades or specific customer requirements.

　　X. Conclusion: The new national standard is not a burden, but also an opportunity for industrial gas companies to upgrade.
　　The implementation of GB/T 6052-2025, “Industrial Liquid Carbon Dioxide,” marks the entry of industrial liquid carbon dioxide quality control into a new phase characterized by greater precision and standardization.
　　For industrial gas manufacturers and gas filling stations, the new national standard brings not only an expansion of testing parameters but also an opportunity to upgrade their quality management capabilities. In the past, companies may have focused solely on oxygen and moisture levels; going forward, customers will place greater emphasis on:
　　Whether total sulfur meets the standard; whether total hydrocarbons are stable; whether carbon monoxide is under control; whether the test data are complete; and whether the enterprise possesses independent quality‑control capabilities.
　　The KR‑GC2032‑ICO2 industrial liquid carbon dioxide gas chromatography method provides a one‑stop solution that meets the analytical requirements for key parameters such as total sulfur, total hydrocarbons, and carbon monoxide as specified in GB/T 6052‑2025. It features low detection limits, high sensitivity, robust instrument configuration, and suitability for routine quality control.
　　For companies that are preparing for the implementation of the new national standard, planning to upgrade their laboratory testing capabilities, or seeking to enhance the competitiveness of their carbon dioxide products for welding applications, this solution represents a key option for building robust industrial liquid carbon dioxide testing capacity.