Fused-silica capillary tubes metal coated

The column tubing itself must be stable at the necessary temperature. The poly-imide scratch-protective outer coating of fused-silica capillaries is itself stable only to about 380°C. Some exceptional stationary phases can exceed this limit, and may require use of metal capillaries, which for some analytes at those temperatures must be deactivated— perhaps with an inner coating of silica, which will not yield a flexible column coil. 

Capillary column A small-diameter chromatographic column for GC or HPLC, fabricated of metal, glass, or fused silica. For GC, the stationary phase is a thin coating of liquid on the interior wall of the tube for HPLC, capillary columns are often packed. Capillary constant The product where m is the mass of... 

The heart of the chromatograph is the column the first ones were metal tubes packed with inert supports on which stationary liquids were coated. Today, the most popular columns are made of fused silica and are open tubes (OT) with capillary dimensions. The stationary liquid phase is coated on the inside surface of the capillary wall. The two types are shown in... 

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