Liquid Chromatography Technology

Liquid Chromatography (LC) is chromatography technology using a liquid as the mobile phase. The liquid phase instrument consists of a degasser, sampler, pumps, and a detector. If necessary, it can be equipped with a gradient elution device, online degasser, autosampler, pre-column or guard column, and column temperature controller. Present-day liquid chromatography technology that generally utilizes very small packing particles and relatively high pressure is referred to as high-performance liquid chromatography technology (HPLC). Various detectors are in common use, such as UV/Vis, photodiode array (PDA), or based on mass spectrometry.

Fig.1 Schematic diagram of liquid chromatography principle.

• Sample introduction
  The sample is first introduced into the liquid chromatograph.
  The sample is moved down the packed tube with a liquid (mobile phase) forced through the column by high pressure delivered through a pump.
• Sample detection
  The separated components are detected by a detector at the outlet of the column, and a chromatogram is formed by data analysis.
• Fraction collection
  Frequently, there is a fraction collector immediately downstream of the detection system to collect the separated molecules.

• High resolution and sensitivity: up to 0.01ng, injection volume in the order of μL.
• Fast analysis speed: ten minutes to dozens of minutes can be completed.
• Good repeatability: the column can be used repeatedly.
• High quantitative precision: automatic operation.
• Wide application range: suitable for the analysis of high boiling points, macromolecules, strong polarity, and poor thermal stability of compounds.

• Life science: analysis of important life substances such as amino acids, polypeptides, proteins, nucleobases, nucleosides, nucleotides, and nucleic acids (RNA, DNA).
• Drug: purification and quality control of synthetic drugs, separation and preparation of active ingredients of Chinese herbal medicines and determination of their purity, and separation and analysis of pharmacokinetic studies in clinical medicine.
• Food: analysis of the composition of food itself, food additives, and food contaminants.
• Environmental: separation and analysis of organic pollutants with large molecular weight, low volatility, and poor thermal stability.， such as herbicides, pesticides, organic pesticides, industrial dyes, etc.
• Chemical products: analysis of chemical raw materials and various chemical products such as surfactants, drugs, pesticides, dyes, etc.

Autosamplers and Injectors

Devices for automated sample injection on gas, ion, liquid (LC), and HPLC columns; includes accessories and replacement parts. Choose from a wide range of high-precision, low-cost, metal-free, high-sample-capacity autosamplers and manual injectors to suit your application needs.

Chromatography Pumps

Chromatography pump is an associated equipment of overall chromatography system. These pumps are used to pass a pressurized liquid solvent containing the sample mixture through a column filled with a solid adsorbent material, leading to the separation of the sample components. We offer a variety of chromatography pumps for your choice.

Chromatography Systems

Chromatography systems include all the equipment needed for sample separation, a power source and program software. Important considerations when selecting a chromatography system are the chemical and physical properties of the substance such as chemical reactivity, size, mass and shape and requirements of the laboratory, such as flow process, validation requirements and sample tracking.

Chromatography Columns

Chromatography is an analytical technique that separates components in a mixture. Chromatographic columns are part of the instrumentation that is used in chromatography. Columns play a central role in the performance of chromatographic process. Well-packed columns with consistent performance in the whole design space of a process will deliver consistent product recovery and separation from contaminants.

Chromatography Detector

A chromatography detector is a device used in gas chromatography (GC) or liquid chromatography (LC) to detect components of the mixture being eluted off the chromatography column. The function of the detector is to convert the change of the sample composition and content in the chromatographic column effluent into a signal that can be detected.

Chromatography Fraction Collector

The fraction collector is typically a rotating rack that can be filled with test tubes or similar containers. If the chromatographic separation is not for pure chromatographic analysis, but for other spectral identification, or to obtain small-scale preparation of a small number of test samples, fraction collection is necessary, and fraction collector collection is ideal and accurate in operation.

STEMart provides you with a variety of liquid chromatography technology equipment to help you quickly and efficiently separate and analyze to meet your various R&D and application needs. If you have any questions or requirements for chromatography equipment, please feel free to contact us.