I. Industry Background and Purification Needs
In fields such as pharmaceutical R&D, natural product extraction, fine chemicals, and biopharmaceuticals, efficiently isolating high-purity target compounds from complex mixtures has always been a core challenge in both research and production. With the continuous expansion of new drug R&D pipelines and the rapid rise of novel therapeutic molecules such as peptides and oligonucleotides, downstream purification processes are placing unprecedented demands on separation technology in terms of efficiency, purity, and scalability.Traditional column chromatography methods suffer from long separation cycles, low resolution, and poor reproducibility, making it difficult to meet the dual demands of modern R&D for throughput and quality. Medium-pressure preparative liquid chromatography (MPLC), as a key technological step between analytical HPLC and industrial preparative chromatography, has become a mainstream choice for separation and purification from laboratory to pilot scale, owing to its excellent balance between separation efficiency, loading capacity, and operating cost.
As a leading domestic analytical instrument enterprise deeply engaged in the liquid chromatography field for 30 years, Elite relies on independently developed pump technology, detector technology, and chromatographic column packing technology to build a complete product line ranging from analytical and semi-preparative to industrial preparative systems, providing integrated solutions for separation and purification needs of different scales and scenarios.
II. Elite Medium-Pressure Preparative Liquid Chromatography System Core Product Line
2.1 3140AP Semi-Preparative LC System — Integrated Analytical and Preparative Dual-Mode
The 3140AP semi-preparative LC system is a cost-effective entry-level preparative platform launched by Elite for laboratory purification scenarios, innovatively adopting an integrated analytical-preparative dual-mode design. The system flow rate range covers 0.1–40.00 mL/min, meeting the precise analysis needs of microgram-scale samples while also accomplishing gram-scale preparative purification tasks, achieving seamless transition from analytical methods to preparative methods. Through the same solvent delivery system and detection platform, combined with columns of different specifications, the system can flexibly switch between analytical and preparative modes without replacing the main unit.
The system adopts a series constant-flow pump design to ensure low-pulsation solvent delivery and maintain excellent flow stability over a wide flow rate range. Users can flexibly configure an automatic fraction collector according to purification needs, enabling fully automated operation from injection and separation to collection, greatly reducing errors caused by manual operations. For initial active compound screening in drug discovery, preliminary fractionation of natural products, and routine purification work in university research laboratories, the 3140AP is an ideal choice balancing performance and cost.
2.2 EClassical 3500/3700 Semi-Preparative LC Systems — Robust and Efficient Purification Workhorses
The EClassical 3500/3700 series semi-preparative LC systems are the core flagship models of Elite's preparative product line, specifically designed for large-scale purification in pharmaceutical R&D and production. The system flow rate range is as wide as 0.01–100.00 mL/min, with setting increments as fine as 0.01 mL/min, and a maximum working pressure of up to 30 MPa, capable of adapting to the separation needs of preparative columns with different particle sizes and specifications.
In terms of solvent delivery performance, the P3500 high-pressure constant-flow pump adopts patented plunger drive technology. By optimizing the cam curve design and plunger seal structure, it effectively reduces pulsation and wear, extending pump service life. Flow accuracy is controlled within ±1.0%, and flow stability RSD ≤ 0.3%, ensuring precise reproducibility of mobile phase ratios during gradient elution. The integration of an intelligent multi-volume gradient mixer and high-flow flushing function significantly improves the separation efficiency of complex samples and system flushing speed, effectively shortening purification cycles.
For detection, the system is equipped with a full-spectrum UV-Vis detector with a wavelength range of 190–700 nm, supporting full-spectrum scanning and wavelength self-diagnostic functions. Baseline noise is as low as ±0.5×10⁻⁵ AU, ensuring accurate detection of trace components and precise triggering of fraction collection. As the high-configuration version of this series, the EClassical 3700 is widely used in scenarios such as synthetic raw material purification, reference standard preparation, and final product purification, making it an ideal platform for small-scale traditional Chinese medicine R&D and fine chemical purification.
2.3 EClassical 3150 Preparative LC System — Fully Automated Injection and Fraction Collection All-in-One
The EClassical 3150 is a new-generation preparative LC system independently developed by Elite, integrating automatic injection and fraction collection. It mainly consists of three core units: the P3150 high-pressure solvent delivery pump, the D3150 dual-wavelength UV-Vis detector, and the S3150 automatic injection-fraction collector. The system flow rate range is 1–100 mL/min, maintaining flow stability and injection accuracy under different flow rates and injection volumes.
The most distinctive design of this system lies in its tray architecture featuring "free switching between injection and collection, seamless transition between single injection and multiple collections" — each sample tray can simultaneously serve both injection and fraction collection functions, enabling automatic continuous purification of samples. The independent injection and fraction collection tubing design physically effectively avoids cross-contamination, ensuring the purity and batch consistency of purified products. The dual-wavelength detection function can simultaneously monitor two detection wavelengths, facilitating simultaneous tracking of multiple target components in complex matrices.
2.4 S3320 Preparative Automatic Injection-Fraction Collector — Key Component for Purification Automation
The S3320 automatic injection-fraction collector combines automatic injection and fraction collection functions in one unit, meeting both analytical-level micro-injection needs and preparative-level fraction collection capabilities. It adopts advanced mechanical positioning and valve switching technology, combined with detector signal triggering, to automatically complete fraction collection in time-window or threshold mode. The diverse sample vial position design supports large-volume injection and classified collection of multi-component fractions. With the intelligent fraction management function of the Kromstation chromatography workstation, users can monitor the purification process in real time and perform automatic naming and traceability management of collected fractions.
2.5 Elite IPC-50 Series Industrial Preparative Chromatography Systems — Scale-Up from Laboratory to Production
For industrial production scenarios requiring gram-scale to ten-gram-scale or even kilogram-scale purification, the Elite IPC-50 series industrial preparative chromatography systems provide a complete scale-up solution. This series adopts dynamic axial compression column technology, combined with dual high-pressure solvent delivery pumps and a UV online monitoring system, ensuring the stability and reproducibility of the preparative separation process. The dynamic axial compression column can continuously apply axial pressure to the packing during the loading process, maintaining a uniform and dense column bed, effectively avoiding column bed collapse and channeling, and ensuring separation performance and batch reproducibility in large-scale preparation. The dual-pump design enables precise gradient elution at high flow rates, meeting the large-scale purification needs of industrial-grade samples.
III. Technical Advantages
Precise Solvent Delivery Technology：Elite preparative systems adopt independently developed high-pressure constant-flow pump technology, with fully independent intellectual property rights from plunger drive and check valve design to sealing materials. Wide-range flow adjustment covers 0.01–100 mL/min. The low-pulsation solvent delivery design ensures a stable baseline, providing a reliable foundation for accurate quantification of trace impurities and precise fraction collection.
Zero Cross-Contamination Design： Elite has carried out targeted optimization from tubing design and valve selection to flow path structure: independent injection and collection tubing, high-flow automatic flushing function, and minimized flow path dead volume collectively constitute the "zero cross-contamination" technical system. Experimental verification shows that under standard purification conditions, the cross-contamination rate between adjacent fractions is less than 0.1%, demonstrating outstanding performance in applications with extremely high purity requirements such as peptide drug purification and reference standard preparation.
Integrated Analytical and Preparative Capabilities：Users can complete the entire process of analytical method development, preparative method scale-up, and purification execution on the same system platform, without repeatedly transferring methods and samples between analytical and preparative equipment. This greatly shortens the method development cycle from "analytical detection" to "preparative purification," making it particularly suitable for application scenarios requiring rapid response, such as contract research organizations (CROs) and contract development and manufacturing organizations (CDMOs).
Intelligent Workstation and Compliance Management：The accompanying Kromstation chromatography workstation provides full-process intelligent management for preparative purification, supporting Good Manufacturing Practice (GMP)/Good Laboratory Practice (GLP) compliance requirements, with functions such as audit trails, user permission management, and electronic signatures, meeting the data integrity regulatory requirements of the pharmaceutical industry.
IV. Typical Application Scenarios
Peptide Drug Purification：Peptide drugs place extremely high demands on purification technology due to sequence structure similarity and the complexity of synthetic by-products. The EClassical 3500/3700 semi-preparative system, combined with the S3320 automatic injection-fraction collector and Elite's self-produced peptide-specific chromatographic columns and packings, can effectively separate deletion peptides, truncated peptides, and epimers generated during synthesis, with final purity reaching over 99%. For example, in the purification of a peptide composed of 20 amino acids, a single purification run increased crude purity from 65% to 99.2%, with a recovery rate of over 85%.
Natural Product Separation and Purification：Elite preparative systems can flexibly select normal-phase, reversed-phase, or gel filtration separation modes according to the polarity and properties of natural products, achieving gradual separation of components with different polarities through gradient elution strategies. From extracting active monomers from Chinese herbal medicines and separating flavonoids and alkaloids to large-scale preparation of natural product reference standards, the system provides stable and reliable separation performance.
CRO/CDMO Purification Services：Targeting the characteristics of CRO/CDMO enterprises, such as diverse samples, variable demands, and tight delivery schedules, Elite recommends a combined configuration of "analytical system + semi-preparative system": using the EClassical 3200 analytical system for sample detection and method development, and the EClassical 3150 or 3500/3700 preparative system for purification execution. The two systems are method-compatible and data-interoperable, supporting continuous automatic purification of multiple batches of samples and maximizing equipment utilization.
Fine Chemicals and Reference Standard Preparation：In the fine chemicals field, the system can be used for purification of synthetic intermediates, removal of catalyst residues, and preparation of high-purity chemicals. For the preparation of reference standards and control substances, the system's high resolution and high reproducibility ensure the accuracy of product purity and quantitative values.
V. Frequently Asked Questions (FAQ)
Q1: How to choose between a medium-pressure preparative system and high-pressure preparative HPLC?
A2: Medium-pressure preparative systems (working pressure 5–20 bar) are suitable for crude purification and pilot-scale scale-up of milligram to gram-scale samples, offering advantages such as high throughput, low cost, and simple operation. High-pressure preparative HPLC (working pressure above 20 bar) offers higher resolution and is suitable for fine separation of structurally similar components and final product polishing. In actual processes, a combined scheme of "medium-pressure crude purification + high-pressure fine polishing" is often adopted to balance efficiency and purity.
Q2: What are the precautions for packing and maintaining preparative columns?
A2: During packing, ensure the packing is uniform and dense, avoiding air bubbles and channeling. Before use, fully equilibrate with mobile phase; after use, flush promptly to prevent residual sample adsorption. For long-term storage, seal and store in a suitable solvent to prevent the column bed from drying out. Elite provides pre-packed columns and packing services, and can equip guard columns to extend preparative column life.
Q3: How to achieve method scale-up from analytical to preparative scale?
A3: Method scale-up requires maintaining consistent separation selectivity, mainly achieved by adjusting flow rate, injection volume, and column specifications. It is recommended to first optimize gradient conditions on an analytical column, then scale up to a preparative column in proportion to column volume. Elite EClassical series analytical and preparative systems are method-compatible and data-interoperable, effectively shortening the method scale-up cycle.
VI. Summary
With 30 years of accumulated liquid chromatography technology, Elite's medium-pressure preparative LC systems have built a complete product matrix from the 3140AP entry-level model to the EClassical 3500/3700 flagship models, and further to the Elite IPC industrial-grade series, covering purification needs from microgram-scale analysis to ten-gram-scale preparation. Precise solvent delivery performance, zero cross-contamination design, integrated analytical-preparative architecture, and comprehensive automation functions enable Elite preparative systems to demonstrate excellent separation and purification capabilities in numerous fields such as drug discovery, biopharmaceuticals, natural product separation, and fine chemicals.
Choosing an Elite medium-pressure preparative LC system is not merely choosing a separation device, but choosing a complete purification solution from method development to purification production, from hardware to software, and from equipment to consumables. With the cost-effectiveness advantages of domestic instruments and the quality assurance of 30 years of technological accumulation, Elite is committed to providing efficient, stable, and economical separation and purification services for users across various industries.
