SJ/Z 3206.8-1989 General Rules for Sampling and Sample Preparation Methods for Emission Spectrometry Analysis SJ/Z3206.8-1989 Standard download decompression password: www.bzxz.net
This standard specifies the general rules for sampling and sample preparation methods in emission spectrum analysis.
Note: This standard does not include the sampling and sample preparation methods for radioactive, toxic, self-igniting and gas substances.
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Guiding Technical Documents of the Ministry of Electronics Industry of the People's Republic of China General Rules for Sampling and Sample Preparation Methods for Emission Spectroscopy Analysis This standard specifies the general rules for sampling and sample preparation methods for emission spectrum analysis. Note: This standard does not include sampling and sample preparation methods for radioactive, volatile, self-igniting and gas substances. 1 Terminology A part of an object that can represent the properties of the object being analyzed. 1.1 Sample (analysis sample) SJ/Z8206.8—89 1.2 Sampling (collecting samples) The operation of collecting analytical samples from a large number of analyzed objects in accordance with regulations. The collected samples are processed according to the requirements of the analysis method. 1.3 Sample preparation (preparing samples) 2 General principles of sampling and sample preparationwww.bzxz.net 2.1 The sample must be representative The actual sample consumed in emission spectrum analysis is only a few dozen mg. Sample unevenness is the main source of analysis error. Representative samples should be collected and sample preparation measures should be adopted to make the samples uniform so that they can well represent the analyzed object or analysis site. 2.2 The sample should be as consistent as possible with the standard sample. Emission spectroscopy is a relative method. The standard sample is used to determine the known content. The accuracy of the analysis depends largely on the consistency of the sample and the standard sample in processing and chemical properties. This consistency should be maintained as much as possible during sampling, and the difference between them should be minimized during sample preparation. 2.3 Simple and fast. Try not to affect the speed of spectral analysis due to sample preparation. 2.4 Preventing external contamination is particularly important for the determination of low-content elements. 3 Sampling and sample preparation equipment 3.1 Sampling machinery and tools 3.1.1 Cutting and cutting machinery High-speed cutting machines, shearing machines, lathes, drilling machines, saws, etc. are used to sample from a whole piece of metal and make chip samples. 3.1,2 Casting molds Casting molds of various shapes made of steel, cast iron, copper or graphite and refractory materials are used to collect molten samples. 3.1.3 Liquid sample sampling tools, use chemical analysis instruments and utensils. According to the different properties of the liquid, glass, quartz, platinum, polyethylene, polytetrafluoroethylene can be used to make instruments. 3.2 Sample preparation machinery and tools 3.2.1 Small melting furnace To eliminate sample segregation and differences caused by metallurgical process, the sample is remelted. 3.2.2 Grinding and polishing machine The discharge surface of the sample electrode is processed to a certain roughness. Approved by the Ministry of Electronics Industry of the People's Republic of China on February 10, 1989 and implemented on March 1, 1989 SJ/Z8206.8--89 8.2.3 Mixing pulverizer (mortars such as agate, boron carbide, and tungsten carbide can also be used) to crush the sample to a certain particle size, or mix the sample with additives evenly. 3.2.4 Pressure molding machine Press the powder sample into a certain shape of agglomerate in a mold. 3.2.5 Chemical treatment equipment and instruments are used for sample dissolution, burning, enrichment, separation and other operations, such as electric heating plates, ovens, muffle furnaces, etc. and common instruments for chemical analysis. 4 Sample preparation methods The following only includes sample preparation methods for direct spectral analysis. 4.1 Metal solid samples Metal solid samples are rod-shaped and block-shaped. Rod-shaped samples are taken out from molten metal with a casting mold, or re-melted in a small furnace. They are processed into rods with a diameter of 3 to 12 mm, a length of 30 mm, and the top of the required shape. Plate-shaped samples are processed into samples with a diameter of more than 12 mm and a thickness of more than 5 mm. The surface is cut or ground to a certain roughness. Thin plates and filaments are prepared by other sample preparation methods. 4.2 Powder samples Powder samples include powders of metals, salts and oxides, some of which are in the original form of the sample, and some are powdered samples that are chemically treated according to the analysis requirements. 4.2.1 Preparation of Metal Oxides Some metals can be directly oxidized to oxides in a muffle furnace at a certain temperature. Most metals need to be dissolved with acid, converted into salts and then burned into stable oxides. When dissolving, halogen ions should be avoided as much as possible to prevent the formation of volatile halogen salts and the loss of elements. 4.2.2 Preparation of Salts The sample is dissolved with acid, evaporated to precipitate the salts, and then dried at an appropriate temperature. Acids that will not form deliquescent salts of matrix elements should be used to dissolve the sample to avoid affecting the stability of sample excitation. Salt powders are easy to absorb moisture and deteriorate, corrode containers and sample preparation tools, so attention should be paid. Salt powders should not be stored for too long. 4.2.3 Adding Various Additives According to different analysis requirements, various additives are added to the powder sample, such as diluents, binders, buffers, carriers, internal standards, etc., and then mixed evenly with a mixing mill or manual methods. 4.2.4 Pressing and Molding A certain amount of powder sample is placed in a die and pressed into a mass. When analyzing, it is placed in the support electrode or on the surface for excitation. The pressure size and sample quality need to be appropriately selected. Powder samples that do not need to be pressed can directly fill the electrode holes, or a special filling tool can be used to fill a certain mass of powder into the electrode. 4.3 Solution samples In addition to solution analysis samples, when the sample structure has a greater impact on the analysis or the homogeneity is poor, converting the sample into a solution for analysis is an effective solution. Solutions have the advantages of being able to be concentrated, diluted, and adding additives and internal standards. The solvent must keep both the matrix and impurities in the solution, and the dissolution process should not cause the loss of impurities. Mix well before use and do not store for too long. 2 Additional notes, SJ/28208.8-—89 This standard was proposed by the Electronic Standardization Institute of the Ministry of Machinery and Electronics Industry. This standard was drafted by Factory 774 and the Electronic Standardization Institute of the Ministry of Machinery and Electronics Industry. The main drafters of this standard are Wang Jinxue, Zhao Changchun and Huang Wenyu. 3 Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.