Transcript TROBLESHOOTING GAS CHROMATOGRAPHY (GC)

TROBLESHOOTING GAS CHROMATOGRAPHY
(GC)
Parto Zist Behboud
Reza Daj
8/16/2014
Today’s Overview
1
• Introduction
2
• Troubleshooting Approach
3
• Pressure Problems
4
• Leaks
5
• Component Malfunctions
6
• Baseline Problems
7
• Peak Problems
8
• Data Problems
Introduction
Flow
Controller
Injection Port
Detector
Column Oven
Gas Cylinder
Column
Data Processor
Electric
Signal
TROUBLESHOOTING
APPROACH
Do It
Yourself
Reference
Points
Common
Problems
Safety
Getting
the Facts
Isolating
the
Source
Repair
Strategy
Preventive
Maintenanc
e
Sample Injector System
1
•Split/Splitless
2
•On-column Injection
3
•Programed Temperature Vaporization
Detector
Carrier Gas and Detector Gas
Carrier Gas
He and N2 are usually used.
(In the case of a capillary column, helium is desirable)
The gas of 99.999% or more of purity is used.
Detector Gas
TCD ... No need
FID ... H2, Air
ECD ... N2(In the case of a packed column, carrier gas is surely N2.
In the case of a capillary column, N2 is used for makeup gas. )
FTD ... H2, Air
FPD ... H2, Air
BID ... He
Carrier Gas and Detector Gas
Pressure Problems
High Pressure
Pressure Problems
Erratic or Cycling
Pressure
Low Pressure
Leaks
Location the source
Leaks
Column Fitting
Leaks
Piping
Component Malfunctions
Electronic
Problems
Injector
Problems
Flow
Problem
Componen
t
Malfunctio
ns
Detector
Problem
s
Column
Problems
Temperatu
re
Problem
BASELINE PROBLEMS
Noisy Baselines
1. AFC
2. Gradient Temperature
3. Detector
4. Recorder
5. Data System
Drifting or Cycling Baseline
1. Equilibration
2. Late Peaks
3. Temperature
4. Electrical
PEAK PROBLEMS
1
• No Peak or Small Peaks
2
• Bad Peak Shape
3
• Extra Peak
4
• Negative Peak
5
• Incorrect Retention Time
6
• Poor Resolution
PARTO ZIST BEHBOUD
Web: www.Partoz.com
Contact: [email protected]
Tel: 88104115
Fax: 88104117