Sigma-Aldrich products

EMD Millipore’s Aluspher® RP-select B HPLC column is an alkali-stable reversed-phase stationary phase designed for the chromatographic separation of neutral, basic and acidic compounds under neutral conditions. Due to its stability in the pH range of 2-12, Aluspher® RP-select B allows the use of basic eluents, such as NaOH. This suppresses the ionization of basic compounds, and thus avoids peak tailing. Furthermore, advanced formulation technology has enabled the production of spherical alumina particles as a base for Aluspher® 100 RP-select B. The combination of alumina with alkaline eluents has led to new applications in HPLC.

Cellulose is an organic sorbent, which is particularly suitable for the separation of hydrophilic substances by partition chromatography. EMD Millipore’s high-quality cellulose plates include classical TLC or HPTLC grades, and facilitate a wide range of separations. Both plates are available with or without a special fluorescent indicator, which is stimulated to intense blue fluorescent emission at long-wave UV light of 366 nm, and at short-wave UV light of 254 nm.

EMD Millipore’s mixed-bed ion exchangers are a combination of strongly acidic cation exchangers and strongly basic anion exchangers. They include a convenient color indicator, which is characteristic for strongly basic anion exchangers. When loaded, the color indicator of Amberlite MB-3 changes from blue to brown. Transfer into the Na⁺/Cl^- form can be successfully achieved using 10% sodium chloride solution. However, regeneration of mixed-bed ion exchangers back to the H⁺/OH^-form is not possible under laboratory scale conditions.