What is the role of elemental analyzers in the laboratory of elemental analyzers

Elemental analyzers in the laboratory:

Elements are the basic units that make up all substances, and elemental analysis is one of the more common items in the process of material analysis. There are many equipment on the market for elemental analysis, how should we apply it in the actual process, this needs to see the ability of the equipment and what is the purpose of the analysis, the following are several common elemental analysis equipment and its analysis characteristics.

1.Scanning electron microscope (SEM EDS).

This is a fast and convenient method of elemental analysis, which does not require pretreatment, and is generally suitable for micro-analysis because it is equipped with a scanning electron microscope, but because this method does not have a working curve for the sample to be measured, and adopts the form of scanning normalization, it is a qualitative semi-quantitative method, and the accuracy of the results is not enough, and it is suitable for horizontal comparison. This method is widely used for surface analysis, micro-analysis and some simple material screening.

2.Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES).

ICP-OES is a method for elemental quantification based on the emission spectral characteristics of atoms, and the elemental analysis accuracy is high and the detection limit is low due to the need to configure the working curve in the actual analysis process. In addition to the above advantages, it also has the advantages of simultaneous detection of multiple elements, fast analysis speed, good selectivity, and low sample consumption. For accurate results, this method is generally recommended if the sample allows.

It is important to note that this is a consumable method that requires the sample to be digested into a solution form by pretreatment before it can be injected for testing. It is mainly used for metal element analysis, non-metallic element analysis, ceramic element analysis, mineral element analysis, etc.

3.Ion chromatography (IC).

Ion chromatography is a liquid chromatography method that uses the ionic properties of the substances to be measured for separation and detection. It can be used to detect inorganic anions, organic anions, and some biological substances. As the name of the method suggests, the injection is also in liquid form, so the sample generally needs to be pre-treated.

This method is also a method for quantification of working curves, so it is highly accurate and has a low limit of detection. It is mainly used for halogen testing, ion cleanliness of electronic products, ion concentration testing, etc.

4.Organic elemental analysis.

In this method, the sample is burned or decomposed at high temperatures, and the elements to be measured are converted into gases for analysis. The elements tested are carbon, hydrogen, oxygen, nitrogen, sulfur, and the products targeted are mainly organic compounds. This method has a low detection limit and high accuracy.

Samples are consumed during the testing process. It is mainly used for the analysis of organic compounds, carbon, hydrogen, oxygen, nitrogen and sulfur.

The above is the introduction of commonly used element methods, in addition to the above methods, there are also some element analysis methods can also be used, such as carbon and sulfur analyzer, direct reading spectroscopy, Auger electron, X-ray photoelectron spectrometer, etc., in the specific use process can also be combined with its characteristics to choose.

1. Visible spectrophotometer: quantitative or qualitative analysis of substances.

2. Ultraviolet-visible spectrophotometer: quantitative or qualitative analysis of substances.

3. Atomic absorption spectrometer: calcium, magnesium, copper, manganese, nickel, zinc, gold, silver, lead, cadmium, etc.

4. Atomic fluorescence photometer: it can analyze and measure the trace amount of arsenic, mercury, selenium, tin, lead, bismuth, antimony, tellurium, germanium, cadmium, zinc and other elements in the sample.

5. Flame photometer: calcium, magnesium, copper, manganese, nickel, zinc, gold, silver, lead, cadmium, etc.

6. Mercury detector: It can accurately determine the trace amount of mercury in natural water, food, soil and biological samples, especially suitable for environmental monitoring departments at all levels, food hygiene, quality supervision and inspection departments.

7. Kjeldahl nitrogen determination instrument: an instrument that calculates the protein content by measuring the nitrogen content in the sample.

8. Ion chromatograph: measure anions and cations, and the types of inorganic anions are detected: F-, Cl-, NO2-, PO43-, BR-, SO42-, NO3-, CLO2-, BRO3-, CLO3-; Types of inorganic cation detection:

Li+, Na+, NH4+, K+, Ca2+, Mg2+, SR2+, Ba2+, widely used in tap water, environmental monitoring, quality inspection, petrochemical, geological exploration and other fields.

9. Gas chromatograph: an instrument for qualitative and quantitative analysis of complex mixtures of multiple components, such as volatile organic compounds, organochlorine, organophosphorus, polycyclic aromatic hydrocarbons, phthalates, etc.

10. Liquid chromatograph: analysis of food nutrients: proteins, amino acids, sugars, pigments, vitamins, spices, organic acids (phthalic acid, citric acid, malic acid, etc.), organic amines, minerals, etc.; Food Additive Analysis:

sweeteners, preservatives, colorants (synthetic colors such as tartrazine, amaranth, indigo, carmine, sunset yellow, brilliant blue, etc.), antioxidants, etc.; Analysis of food contaminants: mycotoxins (aflatoxins, flavibacterium toxins, E. coli toxins, etc.), trace elements, polycyclic aromatic hydrocarbons, etc.; It is widely used in the analysis and testing of synthetic chemistry, petrochemical, life science, clinical chemistry, pharmaceutical research, environmental monitoring, food inspection and legal inspection.

11. Gas chromatography-mass spectrometer: widely used in environmental protection industry, electronics industry, textile industry, petrochemical industry, flavor and fragrance industry, pharmaceutical industry, agriculture and food safety and other fields; Analysis of organic pollutants in the environment (analysis of pollution in air, water quality, soil); analysis of pesticide residues, veterinary residues and drug residues; Analysis of aroma components of flavors and fragrances; Detection of hazardous substances in the textile industry.

HXS-3AD computer multi-element analyzer is produced by Nanjing Hua Hin Analytical Instrument Manufacturer, is the latest multi-element analyzer in China, which can detect silicon, manganese, phosphorus, copper, nickel, chromium, molybdenum, titanium, rare earth, magnesium, vanadium, aluminum, tungsten, niobium and other elements in carbon steel, high and low alloy steel, stainless steel, cast iron, ductile iron, alloy cast iron, ferromanganese and other materials. There are three large channels, brand computer control, full Chinese menu operation, desktop printer printing results. It can meet the needs of metallurgy, machinery, casting and other industries for multi-element analysis of materials in front of furnace, finished products, incoming materials, etc.

First, the main technical parameters:

1. Analysis method: photoelectric colorimetric analysis.

2. Range range: absorbance value, concentration value.

Take silicon, manganese, phosphorus, nickel, chromium, molybdenum, titanium, rare earths, magnesium in ferrous metals as an example).

mn： p： si： σre：

mg： cr： ni： mo：

TI: 3. Measurement accuracy: in line with GB T223 standard.

4. Measurable elements: silicon, manganese, phosphorus, copper, nickel, chromium, molybdenum, titanium, rare earth, magnesium, vanadium, aluminum, tungsten, niobium, etc.

Second, the main features:

1. The instrument program is compiled in the current popular language, and the operation and display of various functions are adopted to pop up the required function window on the main screen, so that the operator feels that the level is clear and clear at a glance.

2. The instrument is automatically calibrated during the test process to ensure the measurement accuracy, and the built-in multiple curves can meet the analysis needs of a variety of elements.

3. The instrument has established a special database for the printing, storage and query of the analysis result data and curves, and the modification and addition and deletion of the data and curves are very convenient.

The Five Elements Analyzer is a test of the presence of manganese, phosphorus, silicon, carbon, and sulfur in steel. The manganese, phosphorus, silicon, carbon, and sulfur elements in steel are the most important and basic elements, so everyone is used to calling them the five major elements of steel. According to China's current standard GB T5613-1995 cast steel grade representation method and GB T5612-1985 cast iron grade expression method, it is shown that the five major elements are to distinguish the grade and quality of ordinary steel, and its content directly affects the mechanical properties of steel.

Iron and steel and foundry companies regard the inspection of the five major elements of the product as one of the most important tests.

Classification of trace element analyzers:

Trace elements play a special and important role in the chemical process of human life. Medical experts have conducted a lot of research in this area, proving that many diseases are closely related to some trace elements in the human body: for example, zinc deficiency causes children to lose appetite, kidney function, physical growth retardation, brain dysfunction, reduced immunity, etc.; Iron deficiency causes iron deficiency anemia, etc.; Calcium deficiency causes rickets in children, osteoporosis in middle-aged and elderly people, etc.; Excessive lead will affect children's growth and mental development, and in severe cases, lead poisoning will occur.

To engage in basic research and clinical testing in this area, it is necessary to measure trace elements in human blood, urine, and hair.

There are three main types of trace element analyzers on the market.

One is to detect through the optical principle, using the optical principle, through the lens to collect and magnify the image of the nail to be examined, display the invisible things on the TV or monitor, analyze, and then draw conclusions, for the detection of human orthopedics required mineral elements (calcium, iron, zinc, selenium, etc.) is normal. The process is simple** and low, but the test results are inaccurate. Most of them are used to promote the sale of health care products, and hospitals and clinics must not use them.

One is atomic absorption spectroscopy, which atomizes the measured sample through the combustion of the flame to produce a large number of free atoms in the ground state, so as to absorb the characteristic spectral lines of the measured elements emitted by the hollow cathode lamp to complete the measurement process. The test results of this instrument are accurate, but the one-time investment is too large and the operating cost is high. Generally, it is only suitable for hospitals above the third grade.

One is the electrochemical analysis method, the instrument is moderate, the test results are accurate, in line with the requirements of the hospital, there are clear national inspection standards, the one-time investment in the hospital is not high, the operating cost is low, like county-level hospitals, township hospitals, maternal and child health care hospitals, disease control centers, and private hospitals and clinics are the most suitable trace element detectors for electrochemical analysis.

Trace element analyzers are mainly classified into the above types, and customers can choose their own suitable models according to their own needs and economic capabilities.

Elemental analyzer: It is an instrument that can analyze the elements contained in a substance, and can use advanced technology to accurately analyze the substance, and has been widely used. It can detect Si, Mn, P, Cr, Ni, Mo, Cu, Ti and other elements in various materials such as ordinary carbon steel, low alloy steel, high alloy steel, raw cast iron, ductile iron, alloy cast iron and so on.

As a conventional laboratory instrument, the element analyzer can quantitatively analyze and determine the content of C, H, N, S and elements in organic solids, highly volatile and sensitive substances at the same time, and plays an important role in the study of the elemental composition of organic materials and organic compounds. It can be widely used in chemical and pharmacological products, such as fine chemical products, drugs, fertilizers, petrochemical products, carbon, hydrogen, oxygen, nitrogen content, so as to reveal the changes in compound properties and obtain useful information, which is an effective means of scientific research.

The five major elements tested by the elemental analyzer are carbon, sulfur, silicon, phosphorus and manganese in steel. Elemental analysis is used to identify which elements (or ions) are composed of a substance, and this method is called qualitative analysis; It is used to determine the relationship (usually expressed as a percentage) between the components (various chemical components) and is called quantitative analysis. The chemical analysis methods used in the analysis of the five elements of substances can be divided into two categories: classical chemical analysis and instrumental analysis.

The former basically uses chemical methods to achieve the purpose of analysis, while the latter mainly uses chemical and physical methods (especially physical methods are often used in the final determination stage) to obtain results, and some of these analytical methods require the use of more complex specific instruments. The development is rapid, and most of the various analytical work is done by applying instrumental analysis methods, but the classical chemical analysis methods still have their significance. Some large precision instruments measure relative values, while the standard reference materials required for the calibration and calibration of the five major element analysis instruments are generally determined by accurate classical chemical analysis methods.

Therefore, instrumental analysis and chemical analysis are complementary to each other, and it is difficult to completely replace one method with the other.

Metal element analyzers perform qualitative or quantitative analysis of substances based on the unique chemical properties of various elements and their compounds, using the chemical reactions related to them. Quantitative chemical analysis can be divided into gravimetric analysis, titration analysis and gas volume analysis according to the final determination method.

The high-frequency infrared carbon and sulfur analysis instrument and high-frequency induction combustion furnace can quickly and accurately determine the content of carbon and sulfur in ferroalloys, stainless steels, carbon steels, alloy steels, cast iron, ductile iron, non-ferrous metals, rare earth metals, cement, ores, coke, coal, slag, ceramics, catalysts, casting core sand, iron ore, inorganic organic matter and other materials. The product is the crystallization of the integration of international and domestic advanced technology is a collection of optical, electrical, computer, analysis technology in one of the high-tech products, a number of domestic leading technologies, the performance of the whole machine can be comparable to imported products, with a wide range of measurement, strong anti-interference ability, complete functions, simple operation, fast and accurate analysis results and other characteristics.

Main technical parameters of high-frequency infrared carbon and sulfur analysis instruments:

1. Measuring range: carbon:

Sulfur: 2. Analysis error: carbon conforms to ISO9556-89 standard Sulfur conforms to ISO4935-89 standard.

4. Electronic balance: weighing range: 0-120g reading accuracy:

5. High frequency furnace: power: frequency: 18mhz

Main features of high-frequency infrared carbon and sulfur analysis instruments:

1. Infrared detector with low noise, high sensitivity and high stability.

2. The modular design of the whole machine improves the reliability of the instrument.

3. The electronic balance is automatically connected, and the sample can be weighed quantitatively.

4. Windows full Chinese operation interface, easy to operate and easy to master.

5. The software has complete functions, providing more than 40 functions such as file help, system monitoring, channel selection, data statistics, result correction, breakpoint modification, system diagnosis, etc.

6. Dynamically display the data and carbon and sulfur release curves in the analysis process.

7. The measurement linear range is wide and extensible.

8. The design of the high-frequency circuit is reasonable, and the power of the high-frequency furnace is adjustable, which is suitable for the analysis requirements of samples of different materials.

9. The automatic cleaning device of the furnace head can reduce the influence of dust on the analysis results.

10. The heating device of the furnace head makes the conversion rate of sulfur tend to be consistent, and improves the stability of sulfur determination.