Welch Columns in the Spotlight: Shining Stars of the 2025 Edition of the Chinese Pharmacopoeia

The recent official release of the 2025 edition of the Chinese Pharmacopoeia formally included a number of analytical columns from Welch Materials, covering both traditional Chinese medicines and chemical drugs. These inclusions have drawn significant attention across the industry.

The new edition introduces higher standards for pharmaceutical analysis. Whether it's the complex fingerprint analysis of traditional Chinese medicines or the demanding detection of related substances in chemical drugs, Welch columns meet the stringent requirements of the Pharmacopoeia, helping users comply rigorously with regulatory standards and safeguard drug quality and safety.

Thanks to their outstanding stability and wide applicability, Welch columns offer precise and efficient separation solutions for pharmaceutical companies and testing institutions.

In the 2025 edition, Welch columns are recommended in 4 monographs under Volume I and 9 monographs under Volume II. This article summarizes their applications and technical highlights, serving as a reference for analysts worldwide.

Applications:

Technical Highlights:

• Incorporates novel bonding and double end-capping technologies to deliver nearly perfect peak shapes.
• Offers high theoretical plate numbers and peak capacity.
• Exceptional separation performance makes it one of the most versatile C18 columns on the market.

Applications:

Technical Highlights:

• Designed for use under high temperature and low pH conditions (as low as pH 0.5), offering exceptional column lifetime and reproducibility.
• No end-capping: avoids selectivity changes caused by hydrolysis of end-capping agents in acidic environments, ensuring long-term selectivity and reproducibility under low pH.
• Delivers superior peak shapes under low pH conditions, with a selectivity distinct from XB-C18.
• Strong polarity and high surface area: due to the absence of end-capping, LP-C18 is more polar than AQ columns and ideal for retaining and separating polar compounds with excellent peak shape.
• Fully compatible with 100% aqueous mobile phases—functions as an AQ column with better peak shape and resolution.
• Optional 300 Å pore size version available upon request, suitable for separating peptides and proteins under acidic conditions.

Applications:

Technical Highlights:

• Employs Welch’s proprietary organic–inorganic hybrid bonding technology. The silica matrix core retains high mechanical strength and separation efficiency, while the surface is grafted with a highly pH-stable organic hybrid layer. Thus extends pH stability range to 1–12.5.
• Offers consistent performance and long column lifetime even under extreme conditions, significantly outlasting conventional C18 columns under normal use.

Applications:

Technical Highlights:

• Compared to bare silica or amino columns, Ultisil Diol is a much more stable and reproducible normal-phase column.
• Enhanced selectivity and peak shape for certain compounds, based on modified pure silica.
• High column efficiency and extended operational lifetime.

Applications:

Technical Highlights:

• Under reversed-phase conditions, ideal for separating various monosaccharides (yet not suitable for compounds containing aldehyde or carbonyl groups).
• Under normal-phase elution, suitable for polar compounds, tocopherols, and other organics soluble in alkanes, hydrocarbons, and aromatics.
• In low-pH buffer systems, functions as a weak anion exchanger, capable of separating negatively charged molecules and underivatized amino acids.

Applications:

Technical Highlights:

• The Ultisil Amy-D chiral stationary phase consists of spherical silica gel coated with linear amylose derivatives.
• One of the most broadly applicable chiral columns, suitable for compounds with chiral centers such as aromatic, nitro, carbonyl, amide, amino, carboxyl, cyano, hydroxyl, and sulfonyl groups, as well as bulky molecules with asymmetric steric hindrance.