An Overview of Ingredient Analysis

Posted by beauty33 on November 12th, 2020

What is component analysis?

The component analysis of materials refers to the technical method of analyzing the components of products or samples through spectra, and qualitatively and quantitatively analyzing each component. Component analysis or ingredient analysis is mainly used to analyze unknowns and unknown components, and identify materials, raw materials, additives, specific components and content, foreign materials and other information by quickly determining the components in the target sample.

Classification of ingredient analysis

Generally, common substances for component analysis are classified into unknowns, polymer products, fine chemicals, pharmaceutical intermediates, water quality, soil, minerals, metal element analysis, etc. According to the conclusion, the component analysis can be divided into two parts: qualitative analysis and quantitative analysis. Qualitative analysis is mainly to determine the component types of substances, while quantitative analysis is to perform corresponding quantitative analysis after qualitative analysis to obtain the distribution ratio of various components. According to science and technology, quantitative analysis can only be infinitely close to the real situation, but it cannot be 100% accurate.

Material analysis can be divided into three aspects: determination of material structure, observation of material morphology and analysis of material composition. Material composition analysis is mainly to analyze the composition of samples qualitatively and quantitatively through various detection methods.

The purpose of component analysis

Ÿ Understand the ingredients and quality control

Ÿ Used to analyze product formulas, which can quickly restore basic formulas

Ÿ Find evidence for product labeling

Ÿ Prove that the product does not contain an ingredient

Ÿ Find reasons for product performance degradation

Ÿ Understand the content of ingredients to understand product performance

Ÿ Solve problems in the production process

Ÿ Compare products from different periods

Ÿ Can quickly find the cause of unknown objects and eliminate hidden dangers

Ÿ Used for product formulation improvement, imitating production

Common material composition analysis methods

1. Chemical analysis method: An analysis method based on chemical reactions of substances. Each substance has its own unique chemical properties. We can use the chemical reaction between the substances and characterize it in an appropriate way to indicate the progress of the reaction, thereby obtaining the content of certain combination components in the material;

2. Atomic spectroscopy: Atomic spectroscopy is a map of the intensity of the photon absorbed or emitted by the atom and the energy of the photon (usually expressed in wavelength), which can provide relevant information about the chemical composition of the sample. Atomic spectroscopy is divided into three categories: atomic absorption spectroscopy, atomic emission spectroscopy and atomic fluorescence spectroscopy;

3. X-ray energy dispersive spectroscopy (EDX): EDX is often used in conjunction with electron microscopes. It measures the wavelength and intensity of characteristic X-rays generated by the interaction between electrons and samples, thereby qualitatively or qualitatively or Quantitative analysis. Each element has a characteristic X-ray with a specific wavelength corresponding to it, which does not change with the energy of incident electrons. By measuring the type of characteristic X-ray wavelength generated by the electron-excited sample, the elements present in the sample can be determined kind of. The content of the element is proportional to the characteristic X-ray intensity generated by the element, and the content of the element can be determined accordingly;

4. Electronic energy spectrum analysis method: The electronic energy spectrum analysis method uses a monochromatic light source or electron beam to irradiate the sample, so that the electrons in the sample are excited and emitted, and then the intensity and energy distribution of these electrons are measured to obtain material information. The sampling depth of the electron energy spectrum is only a few nanometers, so it is only a reaction of surface components;

5. X-ray diffraction (XRD): XRD can also be used to assist in quantitative analysis of phases. It is because the intensity of the diffraction line of the phase increases as the content increases. However, it is not proportional and needs to be corrected. The phase can be quantitatively analyzed by using the Jade program;

6. Mass spectrometry (MS): An analytical method ionizes the measured substance, separates it according to the mass-to-charge ratio of the ions, and measures the intensity of various ion peaks to achieve the purpose of analysis. Quality is one of the inherent characteristics of a substance. Different substances have different mass spectra (referred to as mass spectra). This property can be used for qualitative analysis; the peak intensity is also related to the content of the compound it represents and can be used for quantitative analysis;

7. Spectrophotometer method: The spectrophotometer uses a light source that can generate multiple wavelengths, and through a series of spectroscopic devices, a light source of a specific wavelength is generated. After the light passes through the sample under test, part of the light is absorbed, and the absorbance value of the sample is calculated, which is converted into the concentration of the sample, and the absorbance value is directly proportional to the concentration of the sample. It includes visible spectrophotometer and ultraviolet spectrophotometer;

8. Spark direct reading spectrometer: The spark direct reading spectrometer uses the high temperature of the electric spark to directly vaporize and excite each element in the sample from the solid state to emit the characteristic wavelength of each element. After a grating splits the light, it becomes a "spectrum arranged by wavelength". "The characteristic spectral lines of these elements pass through the exit slits and are injected into their respective photomultiplier tubes. The optical signals become electrical signals. The electrical signals are integrated by the control and measurement system of the instrument and converted into analog/digital, and then processed by the computer. Moreover, print out the percentage content of each element.