GC-MS ( Gas chromatography–mass spectrometry ) Calibration Procedure

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gc-ms calibration

 

Contents hide
1 Gas chromatography–mass spectrometry Calibration Procedure
2 Sensitivity (GC-MS)
3 Acceptance
4 Repeatability
5 Detector Linearity
6 Acceptance criteria
7 Split Ratio (Gc-Ms)
8 Acceptance criteria
9 Carry Over (GC-MSMS, GC-MS, GC-FID, GC-ECD and Head Space)
10 Acceptance criteria
11 Head Space
12 Acceptance criteria
13 RSD Formula
14 Frequency- Every Six Month
15 Maintenance

 

Gas chromatography–mass spectrometry Calibration Procedure

 

Check
parameters
Acceptance
criteria
Mass Sensitivity
S/N Ratio
> 60:1
Repeatability-RT
GC-MS/MS
FID &
ECD
% RSD MAX
0.5 %
2.0 %
Repeatability-Area
GC-MS/MS                                                FID & ECD
% RSD MAX
5 %
3 %
Detector linearity   
R² ≥ 0.99
Split Ratio                                           
R² ≥ 0.99
Carry-over                                               
Height
should be less than 0.4%

 

Sensitivity (GC-MS)

  • Check the Autotune, Self-calibration and save the calibration details.
  • Prepare the standard octafluoronaphthalene (OFN) in the concentration of 1 pg/ul in iso octane in suitable sample vial.
  • Inject octafluoronaphthalene and run the GCMS.
  • Check the signal noise ratio and mass spectrum of the OFN.

Acceptance

EI Sim Or MRM: S/N> 60 octafluoronaphthalene for 10 ppb molecular ion at m/z 272.

Repeatability

Instrument

Details
Acceptance
criteria
 
 
 
 
 
  GC-MS
Lindane is
taken for calibration of Gc-Ms. Other Gc compounds of known purity can also
be selected as reference material.

Prepare 100 μg
/ml from the stock solution.

 
Inject 5
replicates and calculates the % RSD for the Retention time and Area.

% RSD for Retention time should be ≤ 0.5 %

 

 

 

 

% RSD for Area Should be ≤ 0.5 %

 
 
 
 
 
   GC-FID
Prepare 10%
ethanol in water. Stock volume and final volume can be changed depending on
the availability of micro pipette and volumetric flask. 
Inject 5 replicates
and calculates the % RSD for the Retention time and Area.

% RSD for Retention time should be ≤ 2 %

 

 

% RSD for Area Should be ≤ 3 %
 
 
 
   GC-ECD
Prepare 100 μg/ml
of lindane in ethyl acetate and Inject 5 replicates and calculates the
% RSD for the Retention time and Area.
% RSD for Retention time should be ≤ 2 %

 

% RSD for Area Should be ≤ 3 %

 

 

 

Detector Linearity

Instrument
 Linearity

GC-MS
Prepare 20, 40, 60, 80, 100 ng/ml lindane Calibration
Solution and inject. Plot linearity graph between concentration on the X axis
and Area on the Y axis.

GC-FID
Prepare 0.5, 1, 5, 10, 25, 50 % ethanol in water and inject
in GC-FID. Plot linearity graph between concentration on the X axis and Area
on the Y axis.

GC-ECD
Prepare 20, 40, 60, 80, 100 ng/ml lindane in ethyl
acetate and inject in GC-ECD. Plot a linearity graph between concentration on
the X axis and Area on the Y axis.

Acceptance criteria

 

The correlation coefficient r2 obtained from the
linearity graph for different levels should not be less than 0.99

 

 

 

 

 

Split Ratio (Gc-Ms)

 

Inject same concentration of standard soln at
different split ratio as 1:10, 1:50, 1:100 and record the chromatogram for each
split ratio. Plot a linearity graph between ratio on the X-axis and area on the
Y-axis.

 

 Acceptance criteria

 

The correlation coefficient r2 obtained from the
linearity graph for split ratio should not be less than 0.99

 

 

 

 

Carry Over (GC-MSMS, GC-MS, GC-FID, GC-ECD and Head Space)

 

Keep the vials Containing solvent and analyte in solvent in
the following order.

 

Vial No.

Position
given for reference,

Sample
Details

1.

10

Solvent

2.

11

Std. in
Solvent

3.

12

Solvent

 

Calculate the percentage of carry over as following

 

Carry Over (%) = HCo *100 / Hi

 

Where
       HCo  – peak
height of analyte from vial 12.
       Hi –  peak
height of analyte from vial 11.

 

 

 

Acceptance criteria

 

Height should be less than 0.4%

 

 

 

 

 

Head Space

 

Inject 1 mg/l hexane in oil in 5 replicates and calculate
the % RSD for the Retention time and Area.

 

Acceptance criteria

 

% RSD for Retention
time should be ≤ 0.5 %
% RSD for Area Should be ≤
0.5 %

 

 

 

RSD Formula

 

RSD = STDED * 100 / Avg
 

 

Frequency- Every Six Month

 

Maintenance

  • Check the gas connection, moisture trap condition column connections, any leak in the helium cylinder and change the septa if damaged.

     

  • Run the column conditioning at the end of the sequence.

     

  • After every 50-60 injections the septas are needs to be changed.

     

  • Do bake out the system whenever the vacuum is put down and the moisture is high.

     

  • Clean the liner in every hundred injections depending on the sample matrix analysed.

     

  • Change the wash solvent in the vial daily. Before start of analysis.

     

  • Do a frequent test of gas leakage to avoid any hazard.

     

 

 

 

 

 

 

 

 

 

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