Understanding the Significance of Capillary Columns

1. Understanding the Significance of Capillary Columns Due to advancements made in the later part of 19th century we can truly say that gas chromatography is a mature technique now. If we take into consideration the installed instruments throughout the world the gas chromatography instruments still is far ahead of high performance liquid chromatography instruments. When you setup a gas chromatogram you will purchase accessories, gases and columns with it and column is the most crucial part of the whole purchase if considers each part individually.

2. Thus it is often repeated phrase in the lab fraternity that “Column is the heart of the chromatograph”.  More than 80% of the gas chromatograms use capillary columns nowadays. In present times open- tubular columns as in demand, in this an inert tube of long length is column. In this the free flow of gas is ensured as the center of the tube is open sans any packaging material. Chemical bonding of the stationary phase id done on the inner walls of the tube and is how coating is done. Capillary columns have become such a sought after tools because of ability to bond and cross link the stationary phase. If we want to increase the efficiency of capillary column we just have to replace the capillary column which uses non- cross linked phase and non – bonded phase with bonded and cross linked phase.

3. Now to understand the make of the capillary columns, fused silica, borosilicate glass and stainless steel are the main components. The internal diameter is few tenths of a millimeter. The length can go beyond 10 meters till 60 meters. If the walls if the capillary tubes are coated with a liquid stationary phase, the columns are known as wall coated open tubular (WCOT). Another type is where the inner wall is lines with a support material which is usually thin layered on which stationary phase is adsorbed. An example of this support material is diatomaceous earth. These are popularly known as support coated open tubular (SCOT) capillary columns. If we compare the efficiency WCOT are far superior to SCOT capillary columns.

4. This is the result of higher separation capability of the WCOT columns. The most recent advancement is fused silica open tubular (FSOT) column. It has even thinner walls as compared to glass capillary column. The source of strength is polyamide coating. Other positive features which separate it from other type of capillary columns is low reactivity, high physical strength and flexibility. Liquid chromatography Mass spectrometry (LC-MS) is now routinely used as electrospray ionization (ESI) has been developed which has provided a robust and simple interface.  In biochemistry and other branched of sciences the MS technology along with immunoassay has paved way for better and more economical laboratories. It is a highly chemical identification technique. 

5. To effectively and totally remove solvent of a sample to stop it from going through from the source of ions to the detector and the quadrupole. If we will not remove the solvent the results will not be good and the sensitivity of instrument will be drastically reduced. It is better to get an on-site LC/MS nitrogen generator as it is more economical as compared to purchase of nitrogen for experimentation. Quadrex is one of the premium LC/MC nitrogen generator manufacturing companies that is known for its finesse and class. SOURCE https://quadrexcorp.weebly.com/blog/understanding-the-significance-of-capillary-columns