Articles

Basic Difference of HPLC and GC Technique

by Rohit T. Veeprho Laboratories Pvt.Ltd

High-performance liquid chromatography (HPLC) and gas chromatography (GC) is a multipurpose and very well accepted chromatographic technique utilized for the separation of complex mixtures. HPLC and GC techniques used for identification and quantification purpose but for different intend as its function and application is different.

HPLC and GC is based on the principle where compound subjected on the surface or within a solid or liquid stationary phase by isolating it with the help of the mobile phase.

Following are the differences between HPLC and GC techniques:

 

 

HPLC

GC

Principal

Separation of sample is accomplished by solid stationary phase and liquid mobile phase.

Separation of sample is accomplished by liquid or solid stationary phase and gaseous mobile phase.

Temperature Control

Temp. control approach is not necessary or not required. Generally ambient temp. is required.

Temp. control is much more important as the column is placed inside the oven with control temp. program. Generally higher temp. required for analysis.

Sample State

Separation of liquid state any soluble samples usually with higher molecular weight. 

Separation of volatile and thermally stable samples with low molecular weight.

Column

Column are generally shorter and broader diameter.

Columns are long, normally 10 to 60 meters in length and narrow diameter.

Column Types

Octadecylsilane, Octyl silane, Hexyl, Trimethyl Silyl, Amino, Cyano, TMS, Silica, Hillic, Diol, Ion exchange, Chiral, Phenyl, Gel permeation & Size exclusion chromatography

WCOT, SCOT, PLOT, Carbowax, Polyethylene glycol, Dimethyl polysiloxane, Phenyl methyl polysiloxane, High molecular mass esters, Amides, Hydrocarbons, Polyaromatic compound, Cyanopropyl polysiloxane

Separation

Separation based on the interaction of sample with mobile and stationary phases.

Separation based on the boiling point of sample.

Resolution Issues

Samples with identical polarity

Samples with similar molecular weight

Mobile Phase

Liquids, e.g. Polar solvents like water, acetonitrile, methanol, etc. Non polar solvents like Hexane, Heptane, isopropyl alcohol, dichloromethane etc. 

Gases, e.g. Nitrogen, Helium, Argon, Hydrogen, Oxygen

Speed

Analysis speed is slow.

Analysis speed is fast

Peak shape

Generally, detect bigger or wider peaks which effect lower resolution.

Relatively sharp peaks observed with good resolution.

Detectors

UV-Visible detector, Photodiode-array detection, Refractive index detector, light scattering detector, Charged aerosol detector, Conductivity detector, Fluorescence detector, Chemiluminescence detector,
Optical rotation detector, Mass spectrometric, IR Detector etc.

GC detectors are sensitive and selective, e.g. Flame ionization detector (FID), Thermal conductivity detector (TCD), Electrochemical detector, Electron capture detector, Nitrogen phosphorous detector, Flame photometric detector, Electrolytic conductivity detector, Mass spectrometric, Photo Ionization detector, Reduction gas detector, Catalytic combustion detector, Helium ionization detector etc.

Cost

Less costly

High cost

The selection of instrument is purely based on the nature of sample and requirement of sample.

For more information visit https://veeprho.com/blog/basic-difference-of-hplc-and-gc-technique/


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About Rohit T. Freshman   Veeprho Laboratories Pvt.Ltd

2 connections, 0 recommendations, 28 honor points.
Joined APSense since, August 6th, 2020, From Navi Mumbai, India.

Created on Mar 9th 2021 01:22. Viewed 194 times.

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