About the definition of chemical reagents and the classification of commonly used chemical reagents

Chemical reagent

Early Chemical Reagents only referred to "pure chemicals used to determine the composition or composition of substances in chemical analysis and chemical tests." It was later expanded to "chemicals used to achieve chemical reactions", and the chemicals referred to by "chemical reagents" have long gone beyond this category.

Some people think that "chemicals used in scientific experiments" can be called "chemical reagents." A more comprehensive definition of chemical reagents can be: compounds or elements of various purity levels used in chemical tests, chemical analysis, chemical research and other tests.

HPLC grade high purity Liquid Chromatography solvent

HPLC reagents have the following advantages:

l Low UV absorption;

l Low content of non-volatile substances, free acid, free alkali and moisture;

l Can be used for fluorescence detection.

use:

Used for liquid chromatography (LC) sample preparation, LC sample analysis, LC-MS analysis.

Pesticide Reagent

Pesticide residue reagents have the following advantages:

l Very low pesticide residue background value (≤5 pg/ml), with very few non-volatile components;

l GC control (ECD-PND detection) is of reliable quality and high stability;

l Suitable for the analysis of organochlorine pesticides, organophosphorus pesticides, and PCBs;

l (PCBs) and other compounds detected by GC/ECD and GC/PND;

l Meet the requirements for the analysis of various pesticide residues and the requirements for low volatile impurities.

use:

For gas chromatography detection (ECD, PND), for organochlorine, organophosphorus pesticides, PCBs and other compounds detected by GC/ECD and GC/PND.

In addition, there are ENVISOLV ® reagents specially used for the analysis of dioxins, furans, PCBs and other compounds; used for the gas chromatography (ECD) analysis of high volatile chlorinated hydrocarbons in the environment, and the detection of Aromatic hydrocarbons (FID). OEKANAL® reagent.

Spectrally pure reagents

Spectral pure solvent has the following advantages:

l Low ultraviolet absorption, low infrared absorption;

l Low impurity content;

l Suitable for UV and IR spectrum analysis.

use:

For UV and IR spectrum analysis

Premium pure reagent

Excellent grade pure has the following advantages:

It meets the requirements of international standards, with low metal element impurity content (mostly at ppm level).

use:

Premium pure reagents can be used in most routine experiments, and such products can also be used in the production field.

Special Purity and Synthetic Reagents

Special pure has the following advantages:

The quality standards of extra pure or for synthesis level reagents can meet the configuration of routine solutions in the laboratory or standardized production and use (raw materials for drug synthesis, etc.)

use:

Usually only some important application parameters are tested, such as purity, IR parameters, moisture content and ether content, and peroxide content.

NMR nuclear magnetic resonance solvent

Deuterated solvents are widely used in the field of chemistry research and are indispensable for nuclear magnetic resonance spectroscopy, an important method for analyzing the molecular structure of organic substances.

use:

Nuclear magnetic resonance experiments can provide information about the relationship between atoms and atoms in other molecules, including the spatial orientation and three-dimensional structure of the molecule. It has a wide range of applications in the fields of proteomics, genomics, and drug research.

What are the requirements for deuterated solvents?

NMR is very sensitive to the degree of deuteration of the solvent used. For example, with a 200 MHz spectrum, it is sufficient to use a degree of deuteration of 99.5% to 99.8%. If the level of the equipment is increased, for example, a 600 MHz spectrum is used, higher deuteration is required. Degree of solvent.

Benchmark reagent

The reference compound must be a pure substance within the test accuracy range; the reference solution is used for testing and calibrating the equivalent solution and pH buffer solution; only such a substance can reflect the testing and measuring equivalent solution.

Derivatization reagent

Derivatization refers to a method that connects the component to be tested with a certain specific group by means of a chemical reaction, thereby improving its detection sensitivity and separation effect. The chemical derivatization reaction is used to achieve the purpose of changing the characteristics of the compound, making it more suitable for a specific analysis process, and is widely used in instrumental analysis.

For gas chromatography: To increase the volatility of the sample or improve the detection sensitivity;

High performance liquid chromatography: chemical reaction with sample components, the reaction product is conducive to chromatographic detection or separation.

Ultraviolet spectroscopy: make the tested compound carry a specific group and have ultraviolet absorption.

Infrared spectroscopy: make the tested compound bond with a specific group to have infrared absorption.

Fluorescence detection: with fluorescent chromophore.

The purpose of the derivatization reaction:

Improve the sensitivity of sample detection; improve the resolution of sample mixtures; suitable for further structural identification, such as mass spectrometry, infrared or nuclear magnetic resonance.

Other grade chemical reagents

Ultra-pure grade (puriss+,puriss. p. a ): low metal element impurity content, impurity content is controlled at the ppb or ppt level, suitable for the analysis of inorganic trace metal elements;

Synthetic grade (for synthesis, purum, pure, extra pure): ≥ 95.0%, which can meet the requirements of laboratory test and synthesis;

Technical grade: ≥ 80%, raw materials and auxiliary materials in the laboratory and production stage.