How do I choose the right GC column?

The selection of the proper capillary column for any application should be based on four significant factors: stationary phase, column I.D., film thickness, and column length. The practical effects of these factors on the performance of the column are discussed briefly in this section, in order of importance.

What is a plot column?

PLOT columns generally are made by conglomerates of particles that are deposited as a layer inside of the capillary. The layer is porous, meaning that the gas pressure inside the column also will be present between the individual particles.

How do I select columns in GCMS?

When choosing a column, consider the polarity of both the stationary phase and your target analytes. If the stationary phase and analyte polarities are similar, then the attractive forces are strong, and more retention will result. Greater retention often results in increased resolution.

What are the commonly used types of capillary columns?

Types of gc Capillary columns

PLOT Porous Layer Open Tubular. The stationary phase is the adsorbent, packing, or porous polymer.
SCOT Support Coated Open Tubular. Both support (packing) and stationary phase are added to wall of column.
WCOT Wall Coated Open Tubular.
FSWC Fused Silica Wall Coated Open Tubular column.

How long is a GC column?

Normally capillary GC columns range in length from 15 m to about 60 m. Such column lengths are generally sufficient to resolve complex compounds having closely spaced or even overlapping peaks.

What is film thickness in GC column?

Film thickness in capillary columns, is in general between 0.1 and 10 μm for liquid stationary phases such as Rtx-1, 17 and wax. Mostly used are the 0.25 micron films. Thin films are used for the analysis of high boiling materials and thick films for volatiles.

How many types of GC columns are there?

Two types of columns are used in gas chromatography: packed columns and capillary columns.

What is column in gas chromatography?

The column is the heart of the gas chromatograph. It is through interactions between solutes (individual compounds in the sample, also called analytes) and the stationary phase within the column that separation can occur.

What is DB 5 column?

DB-5 Columns Agilent J&W DB-5 is nonpolar and low bleed, and is available in a range of column dimensions. DB-5 is also bonded, crosslinked, and solvent-rinsable, and has a high temperature limit. It is equivalent to USP phase G27.

What is Scot and WCOT?

General description. Capillary columns are basically of two type wall-coated open tubular (WCOT) and support-coated open tubular (SCOT). WCOT columns consist of a capillary tube, where the walls of the tube are coated with liquid stationary phase.

What is the difference between capillary column and packed column?

The main difference between packed column and capillary column is that, in a packed column, the stationary phase is packed into the cavity of the column whereas, in a capillary column, the stationary phase coats the inner surface of the cavity of the column.

Why are GC columns so long?

However, before entering the GC column: liquids get converted to vapours due to high temperature in the injector block. A gas encounters less resistance in the GC column which permits use of longer column lengths. Such compounds are easily vaporized and remain as gases during passage through the column.

What is the size of a Scot column?

SCOT columns combine the sensitivity and excellent sample resolution of capillary GC with the extensive stationary phase library of packed GC. All our SCOT columns have dimensions of 50 feet x 1/32 inch O.D. x 0.02 inch I.D. and include 1/16 inch O.D. connections at each end.

What is the capillary GC column used for?

SCOT Capillary GC Column may be used for high resolution gas chromatography. It may also be used for the determination of nonhydroxy fatty acid composition of rat brain lipids. Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

What are gas chromatography columns made of?

824 3 Basic Overview on Gas Chromatography Columns are typically made of stainless steel and have an outer diameter of 0.64 or 0.32cm and lengths of 0.61–3.05m.