This document compares and contrasts two analytical chemistry techniques: HPLC (High Performance Liquid Chromatography) and GC (Gas Chromatography). HPLC uses liquid mobile phases to separate compounds based on polarity, while GC uses inert gases and separates compounds based on volatility. HPLC works at room temperature and has shorter, wider columns, while GC operates at higher temperatures and uses longer, thinner columns. HPLC is generally used in pharmaceutical industries for separation of non-volatile compounds, while GC is commonly used to analyze volatile compounds like oils and fuels. Overall, HPLC provides higher resolution for polar compounds but is more expensive than GC.

1. HPLC Vs GC

2. S.No. Parameter HPLC GC
Methods
1 Mobile Phase Liquid Inert Gas
Separation
Techniques
Based On Polarity Based on volatality
Compound
Properties
Soluble (Volatile or non
volatile)
Volatile
Working
Temperature
RT (20-25°C) High Temp. (150-300°C)
Speed Slower Faster
Resolution
Low Resolution for
polarity
Low Resolution for molecular
Weight

3. Equipments
Column
Length
Short & wide
(Length 30cm & internal Dia.
8mm)
Long & thin
(Lenght: 100 m & Internal Dia: 0.1-1
mm)
Solvent Must be polar Must be vaporize
Detection
Non Detective like Ultraviolet-
Visible spectroscopy or
Refractive Index Detector
Destructive like a flame ionization
detector (FID) which is effective for
analysing hydrocarbons. Or a thermal
conductivity detector (TCD) can be
used as it is a universal detection
method for GC analysis
Cost Higher Lower

4. Application
Industries
Inorganic ions,
polymers,
sugars,
nucleotides,
vitamins,
peptides,
proteins,
lipids and
tetracyclines,
Basically Pharmaceutical
Companies
Oils,
plant pigments,
pesticides,
fatty acids,
toxins,
air samples and
Drugs (Intermediates).

5. 1. Lab Demo
2. Calculation:
1. Silica Crucible: 35.93 gm
2. Drug Wt: 2 gm
3. Burnt Drug + Crucible Wt: 36.08 gm
4. Wt of Ash: 36.08-35.93 = 0.15 gm
5. % of ash in 2 gm drug = 0.15 / 2 *100 = 7.5%

6. Title Water Content Loss On Drying
Method
Involves
Chemical Reaction
Drying of Sample under specific
Temp. at std duration
Depends on Quality of reagent used
Temperature
Moisture content
Humidity
Bulk density
Resistance to Airflow
Formula
= Mass of water in sample / mass of
dry sample * 100
= Mass of water in sample / Mass
of wet sample * 100