The document discusses different types of gas chromatography columns. It describes packed columns which contain a solid support material that absorbs the stationary phase. Capillary or open columns have a very thin film coating on the inner wall that acts as the stationary phase. Key parameters that determine column selection and performance are discussed such as diameter, length, film thickness, and stationary phase properties. The advantages of capillary columns over packed columns are their higher efficiency and resolution due to higher ratio of stationary to mobile phase volumes.

1. Presented by –
Komal Shambharkar
M.Pharm (Q.A.)
Guided by-
Dr. Pratima Tatke

2.  Column introduction
 Column Selection Parameters
 Column classification
 Packed column
 Open column
 Images of column
 Difference between capillary column and packed
column
 Conclusion
 References

3.  The column is the most important component of GC.
 Made up of glass or stainless steel
 Glass column- inert , highly fragile
 Here is where the separations take place.
 All the various equations dependent on properties of
the column.

4.  The critical parameters for GC column
 Dimension :internal diameter , column length , film
thickness
 Condition :temperature ,flow rate
 given a sample, we will need to first choose the
stationary phase which works best
 First pick the type of column, then dimension of
column
 Choice of stationary phase is very important
 It determines what kind of sample we can run
 Critical for packed columns, but less so for open
column because of high efficiency

5.  The main chemical attribute regarded when choosing
a column is the polarity of the mixture, but
functional groups can play a large part in column
selection.
 The polarity of the sample must closely match the
polarity of the column stationary phase to increase
resolution and separation while reducing run time.
 The separation and run time also depends on the film
thickness (of the stationary phase), the column
diameter and the column length.

6. COLUMN
PACKED COLUMN OPEN/CAPILLARY
COLUMN
WCOT SCOTPLOT

7. 1.Packed column:
 Column are made up of glass or tubes of stainless steel ,
copper or aluminium
 columns are available in a packed manner
 Packed columns contain a finely divided, inert, solid
support material (commonly based on diatomaceous earth)
which absorbs liquid used as stationary phase
 Most packed columns are 2 - 20m in length and have an
internal diameter of 1- 8mm
 The ratio of the volume of the stationary phase to the
mobile phase (Vs / Vm) for the column ranges from 10-20
 The no. of theoretical plates per foot length of the column
is 100-1000

8.  Advantages :
• Larger sample capacity
 Disadvantages:
• Less applicable :fixed gas analysis
• Lower column efficiency than that of capillary
column

10. 2.Open tubular or Capillary column or Golay column
 Long capillary tubing 10-100 M or more in length
 Internal diameter 0.3-0.5
 Uniform & narrow d.m of 0.025 - 0.075 cm
 Inner layer of capillary is coated with a very thin film
(about 1µ𝑚) 𝑜𝑓 the liquid ,which acts as stationary phase
 The ratio of the volume of the stationary phase to the
mobile phase (Vs / Vm) for the column ranges from 100-
300 which is the main reason behind its high effeciency
 The loading capacity <0.01 µl
 Made up of stainless steel & form of a coil
 Disadvantage: more sample cannot loaded

11. Capillary column are of Three Types
 Wall-coated Open Tubular (WCOT)
 Support-coated Open Tubular (SCOT)
 Porous layer Open Tubular (PLOT)
 Wall-coated columns consist of a capillary tube whose
walls are coated with liquid stationary phase.
 In support-coated columns, the inner wall of the
capillary is lined with a thin layer of support material
such as diatomaceous earth, onto which the stationary
phase has been adsorbed
 SCOT columns are generally less efficient than
WCOT columns. Both types of capillary column are
more efficient than packed columns.

12.  PLOT columns contains a porous layer of a slid
adsorbent such alumina , molecular sieves. They are
well suited for the analysis of light, fixed gases and
other volatile compound.

14.  In 1979, a new type of WCOT column was devised -
the Fused Silica Open Tubular (FSOT) column
FSOT column :
 They have much thinner walls than glass capillary
column
 The strength is given by polyimide coating
 They are flexible and wound into coils
 Advantages are more physical strength, flexibility and
low reactivity

15. Parameter Capillary column Packed column
Internal diameter 0.3- 0.5mm 1-8 mm
length 10-100m 2-20 m
Vs/ Vm 100-300 10-20
No. of theoretical
plates
Several hundred
thousand
Around 20,000
Sample loading
capacity
lower higher
Efficiency of
separation
Higher Comparatively lower
DIFFRENCE BETWEEN CAPILLARY
COLUMN AND PACKED COLUMN

16. Parameter Capillary column Packed column
Efficiency (plates/m) 2000-400 500-1000
Sample size (mg) 10-75 10-100000
Relative pressure Low High
Relative speed Fast Slow
Chemical inertness Best Poorest
Flexible column yes No

17. parameters FSWC WCOT SCOT Packed
Length 10-1000 m 10-1000m 10-100m 1-6 m
Inner
diameter
0.1-0.3 mm 0.25-
0.75mm
0.5mm 2-4mm
Efficiency 2000-4000 1000-4000 600-1200 500-1000
Sample size 10-75ng 10-1000ng 10-1000ng 10-
1000000ng
Pressure Low Low Low High
Speed Fast Fast Fast Slow
inertness Best Good Fair Poor
Types of columns

18.  In Gas Chromatography , the COLUMN is the most
important component as it is interaction of analyte
with the column’s stationary phase that permits
separation of the analyte in the sample.
 And therefore Column play its vital role in Gas
Chromatography being its heart .

19.  Instrumental Methods of Analysis , by Supriya S. Mahajan,
page no.287-290
 Instrumental Methods Of Chemicaal Analysis by Gurdeep
R.Chatwal & Sham K. Anand , 5th edition , page no. 2.673-
2.700
 Basic overview on Gas chromatography columns by Md.
Musfiqur Rahman, A.M. Abd El-Aty, Jeong- Heui Choi,
Ho-Chul Shin, Sung Chul Shin ,and Jae-Han Shim
 “Principles Of Instrumental Analysis, 5 th ed. by Skoog,
Holler, Nieman” Chapter 27.
 https://teaching.shu.ac.uk