Precautions for metal composition analysis samples
Date：2026-01-13 13:19:18 Classification
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Metal composition analysis requires careful control at multiple stages, including sample preparation, testing procedures, and quality control. Specific precautions are as follows:
I. Sample-Related Precautions
1. Sample Collection and Storage
Ensure sample representativeness, avoiding cutting edges, oxide layers, or welded areas. It is recommended to provide at least three parallel samples to reduce errors. For special samples such as plating or welds, clearly label the testing location.
Avoid contamination. Use containers and tools that do not come into contact with metals. Cut solid samples into 5-10g pieces. Store powdered or liquid samples in sealed containers and properly label sample information to prevent confusion.
2. Sample Pretreatment
Perform pretreatment according to the analytical method requirements, such as dissolution, digestion, and volatilization, to ensure the solubility and detectability of metal elements during analysis. Clean samples beforehand to remove surface contaminants or oxide layers.
II. Precautions for Selecting Detection Methods and Instruments
1. Differentiating Metal Material Types
Different types of metal materials have significantly different compositions and properties. Before analysis, materials must be classified, and a matching analytical scheme selected.
2. Consider Processing and Heat Treatment Conditions
The processing and heat treatment conditions of metallic materials affect their composition. This factor must be considered during analysis to ensure the results reflect the compositional characteristics relevant to the material's actual properties.
3. Match Analytical Methods and Instruments
Select appropriate methods and instruments based on the sample matrix, target analyte, and detection limitations: For routine macro-elements, chemical analysis methods such as titration and gravimetric methods can be used; for trace or complex components, instrumental analysis such as spectroscopic analysis (e.g., OES, XRF) and mass spectrometry can be used; for export products, the target market standards (e.g., EU EN10276, US ASTM E1019) must be clearly defined, and corresponding testing methods must be matched.
III. Quality Control and Operational Precautions
1. Sample Calibration and Quality Control
Use standard curves or calibration curves for quantitative analysis, and simultaneously conduct quality control testing, such as using internal standard materials, repeated measurements, and reference material verification, to ensure the accuracy of the results.
2. Laboratory Operation Safety
Strictly follow laboratory operating procedures and safety regulations to ensure the safety of the experimental environment and personnel, especially in areas involving high-temperature digestion and the use of chemical reagents.
3. Data Analysis and Interpretation
The test data is carefully analyzed and interpreted. Quality control measures such as repeated measurements and blind sample testing are used to verify the reliability of the results. The compliance of the components is determined in conjunction with relevant standards, and the meaning and limitations of the results are accurately explained.
IV. Report and Follow-up Precautions
1. Report Validity
The validity period of a metal composition analysis report is typically 1-2 years. If the raw material batch or production process changes, retesting is required.
2. Selection of Testing Institution
Prioritize third-party laboratories with CMA/CNAS accreditation (e.g., Dezewei Testing CNAS Registration No.: L8083) to ensure their testing scope covers the target metal types (e.g., stainless steel, aluminum alloys), guaranteeing the report's authority and acceptance.
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