Frequently Asked Questions

Yes. Exmere offers a complete white-label production service — columns are manufactured to your exact specifications and shipped with your brand name, your Certificate of Analysis format, and your documentation. You define the specification; we handle silica synthesis, bonding, packing, testing, and dispatch. There is no requirement to disclose your production partner. This model allows distributors, instrument companies, and specialty labs to offer premium HPLC columns without investing in manufacturing infrastructure.

White-label HPLC column manufacturing means an OEM producer manufactures columns that are then sold under another company's brand. The buying company defines the product specification, brand name, and packaging. The manufacturer handles everything from raw silica through to tested, documented columns ready for resale. For HPLC column companies, white-label manufacturing eliminates the need for packing equipment, specialised staff, and quality infrastructure — typically reducing time-to-market from years to weeks.

The most direct route is to partner with an established OEM manufacturer who handles production while you build the commercial side of the business. You define your target applications and specifications, approve prototype columns, establish your brand, and focus on sales. An OEM partner like Exmere handles everything from silica synthesis through to packed, tested, documented columns — shipped under your label. Most partners launch their first product SKU within weeks of initial sample approval.

At Exmere, there is no minimum order quantity — we produce from a single column upwards. For new product development, prototype quantities of 5–10 columns are typical. For established programs, orders of 100–10,000 columns are common. Customers with predictable annual volumes can participate in our hot runner stock program, where pre-produced columns are held for dispatch within 3–4 business days — with no minimum order on top of the annual commitment.

Standard delivery for custom HPLC columns from Exmere is one week from order confirmation. For new specifications requiring silica synthesis or phase development, lead times for first-article prototype samples are typically 4–8 weeks. Once a specification is established and validated, reorders follow the standard 1-week timeline. Customers with agreed annual forecasts can access our hot runner stock program — enabling 3–4 business day dispatch for their most frequently ordered SKUs.

In-house HPLC column production requires a minimum investment of around €100,000 in equipment plus annual fixed overhead exceeding €120,000 for staff, maintenance, and compliance. When all costs are accounted for honestly — including raw material inventory, QC rejection rates, instrument downtime, and management time — own production becomes cost-competitive only above approximately 4,000 columns per year for a single SKU. Companies producing lower volumes, or distributing volume across a broad portfolio of phases and dimensions, typically find outsourcing significantly more cost-effective.

The most commonly overlooked costs include: raw material inventory tied up as working capital (silica, column blanks, solvents — often €30,000–50,000 at any time); a QC rejection rate of 4–8% on packed columns that must be disposed of; annual product liability insurance; compliance documentation and audit preparation time; ultrapure water system (MilliQ) maintenance; annual instrument calibration; hazardous solvent disposal; and the management overhead of retaining specialised production knowledge in-house. Together, these typically add €30,000–50,000 per year beyond headline equipment and staff costs.

Several companies offer HPLC column OEM manufacturing, but most specialise in a single step of the process — either silica production or column packing. Exmere is one of the few OEM manufacturers that controls the full production chain: custom silica synthesis, stationary phase bonding, column packing, and QC — all under one roof and one quality system. This means a single contract, single point of accountability, and complete traceability from raw silica lot to finished, shipped column.

High-Performance Liquid Chromatography (HPLC) is an analytical technique used to separate, identify, and quantify the components of a mixture. A sample is dissolved in solvent (mobile phase) and pumped under high pressure through a column packed with particles (stationary phase). Different components interact differently with the stationary phase, travel at different speeds, and exit the column at different times. HPLC is used extensively in pharmaceutical analysis, food testing, environmental monitoring, biochemistry, and chemical research — making it one of the most widely used analytical techniques in the world.

HPLC columns are manufactured through slurry packing: silica particles are suspended in a solvent to form a high-concentration slurry, then forced into the column body under high pressure (typically 300–1,000 bar). The packing process is critical — poor packing results in reduced efficiency, high backpressure, and poor peak shape. After packing, every column is tested against performance specifications (plate count, asymmetry factor, backpressure) and a Certificate of Analysis is issued. At Exmere, silica synthesis, bonding, and slurry packing all take place in-house under a single quality system.

Type A silica (older technology) contains significant metal impurities — particularly iron, aluminium, and calcium — which interact with basic analytes, causing peak tailing, poor reproducibility, and short column lifetime. Type B silica (modern standard) is synthesised with very high purity, with metal content reduced by orders of magnitude. Type B silica produces far more symmetrical peaks for basic compounds, better lot-to-lot reproducibility, and longer column lifetime. All silica produced by Exmere is Type B high-purity material.

Monodisperse silica consists of particles with a very narrow, uniform size distribution — in contrast to polydisperse silica where particle diameters vary more widely. Uniform particle size produces more homogeneous column beds, lower backpressure for a given efficiency, better peak symmetry, and more consistent performance between columns and production lots. Monodisperse particles are particularly advantageous for sub-2-micron UHPLC applications, where even small variations in particle diameter significantly affect column backpressure and efficiency.

After bonding a stationary phase (e.g. C18) to the silica surface, a proportion of silanol groups (Si-OH) remain unreacted. These residual silanols can interact with basic and polar analytes, causing peak tailing and variable retention. Endcapping involves reacting residual silanols with a small silylating agent (commonly trimethylchlorosilane) to chemically cap them. Endcapped phases produce significantly better peak symmetry for basic and polar compounds, and are preferred for pharmaceutical, biological, and method development applications.

Fully porous particles consist entirely of porous silica, and analytes diffuse through the complete particle volume during separation. Core-shell (superficially porous) particles have a solid, non-porous silica core surrounded by a thin porous outer shell. The solid core reduces the diffusion path for analytes, resulting in higher efficiency (sharper peaks) at a given particle size, and lower backpressure than equivalent sub-2-micron fully porous particles. Core-shell columns are increasingly used as a high-efficiency option that works within the pressure limits of conventional HPLC systems without requiring UHPLC hardware.

The choice of particle size involves a trade-off between efficiency, analysis speed, and system pressure. 5 µm particles are the traditional choice — robust, compatible with all HPLC systems, and adequate for most routine applications. 3 µm particles give higher efficiency and faster runs at moderately higher pressure. Sub-2-micron particles (1.7–1.8 µm) deliver the highest efficiency and fastest analysis but require UHPLC systems capable of 600–1,000 bar. For routine analytical work, 3 µm offers a good balance. For UHPLC method development or highest-resolution work, sub-2-micron is preferable.

Phase selection depends on analyte polarity, required selectivity, and the mobile phase system. C18 (octadecyl) is the most universal reversed-phase choice and the best starting point for most non-polar to moderately polar analytes. C8 and C4 offer shorter chain retention, preferred for very hydrophobic compounds. Phenyl and phenyl-hexyl phases offer orthogonal selectivity for aromatic compounds. For polar analytes and aqueous mobile phases, HILIC phases are appropriate. For charged analytes, ion exchange phases apply. Exmere offers over 100 bonded phase chemistries — contact us to discuss your specific application.

These designations refer to the length of the carbon chain bonded to the silica surface. C18 (18-carbon chain) provides the highest hydrophobic retention, making it the most versatile reversed-phase choice. C8 (8 carbons) gives slightly less retention and is useful where C18 retention is too strong. C4 (4 carbons) provides minimal hydrophobic interaction and is commonly used for large biomolecules such as proteins and peptides, where strong surface interaction risks irreversible adsorption or denaturation. The silica substrate quality and bonding density are equally important as chain length in determining real-world selectivity.

Hydrophilic Interaction Liquid Chromatography (HILIC) uses a polar stationary phase with a high-aqueous mobile phase — essentially the inverse of reversed-phase HPLC. HILIC retains polar and hydrophilic compounds that are not retained on C18. It is particularly useful for small polar molecules, amino acids, nucleotides, sugars, and pharmaceutical polar impurities that are too hydrophilic for conventional RP-HPLC. HILIC is also highly compatible with mass spectrometry due to the high organic content of the mobile phase, making it popular in bioanalytical, metabolomics, and clinical research applications.

Pore size determines which molecules can access the internal surface area of the silica particle. For small molecules below 2,000 Da, 100 Å pore silica is the standard choice and provides the highest surface area and retention. For medium-sized molecules such as peptides, 150–200 Å pores allow better internal access. For large molecules — proteins, antibodies, synthetic polymers — 300 Å or larger pores are required to prevent size exclusion from the pore structure and the poor peak shapes and low recovery that result. Exmere can synthesise custom pore sizes for specialist applications.

Silica bonding refers to the chemical process of attaching functional groups — such as C18, phenyl, or NH2 — to the surface of silica particles to create the chromatographic stationary phase. The bare silica surface carries reactive silanol groups (Si-OH), which are reacted with organosilane reagents (e.g. octadecyltrichlorosilane for C18) under controlled temperature and atmosphere conditions. The resulting bond is covalent and stable under typical HPLC operating conditions. Bonding density, coverage uniformity, and the degree of subsequent endcapping directly determine column performance, selectivity, and operational lifetime.

Analytical HPLC columns (typically 2–4.6 mm internal diameter) are designed for analysis — separating and quantifying components at microgram to milligram scale. Preparative columns (typically 10–300 mm ID) are designed for isolation — collecting larger quantities of pure material, from grams to kilograms. Preparative columns contain significantly more stationary phase, operate at higher flow rates, and are loaded with much higher sample amounts. The fundamental principles of chromatographic separation are identical; scale-up requires proportional adjustment of flow rate, sample mass, and solvent volume relative to column cross-sectional area.

Scale-up from analytical to preparative HPLC is based on maintaining the same column bed length and stationary phase chemistry while increasing the column diameter proportionally to the target throughput. The linear velocity — flow rate divided by column cross-sectional area — should be kept constant to maintain separation performance. Sample loading scales proportionally to column volume. Exmere manufactures columns at all scales from 2 mm analytical to 300 mm process-scale, using the same silica and bonded phase chemistry across formats — ensuring consistent selectivity from method development through to production.

Exmere produces HPLC columns across the complete format range: capillary columns from 50 µm internal diameter for nano-LC and chip-based applications; micro columns (0.5–2 mm ID); standard analytical columns (2–4.6 mm ID); semi-preparative columns (8–21 mm ID); preparative columns (25–80 mm ID); and process-scale columns up to 300 mm internal diameter. Column lengths range from 20 mm to 300 mm. Custom dimensions are available on request. All formats are produced using the same stationary phase portfolio, ensuring consistent chemistry from development to production scale.

Yes. Exmere offers custom silica synthesis covering particle diameter (from sub-2-micron to 10 µm and beyond), pore size (60 Å to 1,000 Å and larger), pore volume, and surface area. Custom specifications are developed in collaboration with the customer and fully validated before production commitment. A custom silica batch can then be reserved exclusively for one customer's product, ensuring raw material consistency across the lifetime of the product. Enquiries for custom silica development are welcome regardless of initial volume — please contact us to discuss your requirements.

A Certificate of Analysis (CoA) is the quality document issued for each column or column batch, confirming that the product meets its defined performance specifications. A typical HPLC column CoA includes: column identification (part number, lot number, serial number); key performance data measured on a reference standard compound (theoretical plate count, peak asymmetry factor, backpressure); the mobile phase and test conditions used; and the acceptance limits against which each column was tested. Exmere issues a full CoA for every column produced, and can issue documentation in your format for white-label programs.

A silica batch reservation means that a specific lot of synthesised silica — produced to your exact specification — is permanently reserved for use in your product only. No other customer's product uses material from that batch. This eliminates inter-lot silica variability as a source of column-to-column performance differences, which is critical for pharmaceutical and regulated applications where method validation is performed on a specific column and must remain valid across future supplies. Exmere offers silica batch reservation as standard for OEM customers with established product commitments.

Lot-to-lot reproducibility depends on controlling three primary variables: silica raw material consistency, bonding process control, and packing process control. At Exmere these are managed through: silica batch reservation (the same raw material lot across all orders for a given product); documented and validated bonding procedures with in-process analytical controls; and standardised packing parameters with 100% column testing against acceptance criteria on every production run. Every column is tested against the same reference standard under identical conditions — ensuring that columns produced months apart perform identically within the defined specification limits.

Standard documentation with every Exmere OEM shipment includes: a Certificate of Analysis with full performance test data and test chromatogram; a column identification label with lot number, traceability code, and storage conditions. For white-label programs, all documentation is issued in your format and under your brand name. On request we can additionally provide: silica raw material certificates; bonding batch records; packing process records; and stability data. For regulated and pharmaceutical applications, additional documentation to support supplier qualification audits, change notifications, and regulatory submissions is available.

USP L1 is the column classification used in the United States Pharmacopeia (USP) for octadecylsilane (C18) chemically bonded to porous silica or ceramic particles — the most widely specified phase type in pharmaceutical monographs worldwide. In practice, L1 columns can vary significantly in chromatographic selectivity between manufacturers, because silica purity, bonding density, endcapping degree, and particle morphology all differ despite all meeting the L1 definition. For method development intended to support regulatory submissions, column brand and lot consistency are critical considerations beyond the L1 designation. Exmere C18 phases are fully suitable for use in USP L1-specified analytical methods.