6 Helpful Hints for Using and Choosing

Ferrules should be replaced every time you replace a column and when performing column maintenance. Below are six helpful hints for using and selecting the proper ferrules for your application.

1. Using New Ferrules Is Important
 
Ferrules are the most common devices in both GC and LC applications for sealing tube connections to contain high-pressure gases and liquids in chromatography systems. Ferrules provide higher structural integrity and inertness than other choices, such as plastic and rubber o-rings. Essentially, a column nut compresses the ferrule into a column tube connector designed specifically for the ferrule’s shape. This compression squashes the ferrule to create a tight seal, in the process deforming the ferrule. Ferrule re-use, therefore, may compromise a tight fit and potentially cause leaks.

2. Matching Ferrules, Column Nuts, and Tubing Matters
 
It is important to match nuts and ferrules that are specifically designed for their tubing (usually designated by the outside diameter of the tubing). Incompatible ferrules and column nuts can cause:

• Potentially dangerous leaks and costly repairs to column interfaces.
• An improper seal at the injector (resulting in high column bleed and shortened column life).
• Increased detector signal/noise.
• Oxidation of the ion source in MSD, increasing the frequency of detector maintenance.
• Leaks that allow air and other contaminants to enter the instrument (for inconsistent and unreliable chromatography).

 

Inlet and standard detector connections
Recommended		Traditional		Inert Flow Path
Nut 5190-6194	Column nut,Self Tightening Inlet/Detect	Nut 5181-8830	Universal column nut, 2 pk	Nut 05921-21170	Column nut for long ferrule
Ferrule 5181-3323	Ferrule, 0.4mm VG 0.1-0.25 col 10/PK	Ferrule 5181-3323	Ferrule, 0.4mm VG 0.1-0.25 col 10/PK	Ferrule G3188-27501	Ferrule, flexi inert  0.25mm col 10/PK
5062-3514	Ferrule, 0.5mm VG 0.32 col 10/PK	5062-3514	Ferrule, 0.5mm VG 0.32 col 10/PK	G3188-27502	Ferrule, flexi, inert 0.32mm col 10/PK
Tools G3440-80217	Column install pre-swaging tool, graphite ferrules	Tools G3440-80217	Column install pre-swaging tool, graphite ferrules	Tools G3440-80218	Column install pre-swaging tool, metal ferrules

 

 

MS interface connections
Recommended		Traditional		Alternate
Nut 5190-5233	Column Nut, Self Tightening MSD	Nut 05988-20066	Column Nut for MS interface	Nut G2855-20555	Swaging nut,Ultimate Union and QuickSwap
Ferrule 5181-3323	Ferrule, 0.4mm VG 0.1-0.25 col 10/PK	Ferrule 5062-3508	Ferrule, 0.4mm VG cond .25 col lng 10/PK	Ferrule G3188-27501	Ferrule, flexi inert  0.25mm col 10/PK
5062-3514	Ferrule, 0.5mm VG 0.32 col 10/PK	5062-3506	Ferrule, 0.5mm VG cond .32 col lng 10/PK	G3188-27502	Ferrule, flexi, inert 0.32mm col 10/PK
Tools G1099-20030	Column Installation tool for 5973/5975	Tools G1099-20030	Column Installation tool for 5973/5975	Tools G2855-60200	Ferrule Pre-Swage Tool, Capillary Flow
G3880-20030	5975T Column Insertion Tool	G3880-20030	5975T Column Insertion Tool

 

3. Signs that a Ferrule Needs to be Replaced

• Background noise from oxygen diffusing into the system
• Column bleed catalyzed by oxygen
• Sample degradation
• Loss of sample
• Increase in detector signal/noise
• Poor retention time reproducibility

4. GC Ferrule Quick Selection Guide

 

Ferrule Material and Use	Ferrule id (min)	Use With Columns Of This id (min)	Part No.
Graphic Short Ferrules (General Purpose)	0.5	0.1, 0.2, 0.25, 0.32	5080-8853
	1	0.53	5080-8773
85% Vespel, 15% Graphite Short Ferrules (General Purpose)	0.4	0.1, 0.2, 0.25	5181-3323
	0.5	0.32	5062-3514
	0.8	0.45, 0.53	<a title="" href="//wwwa title=" "="">5062-3512
Preconditioned 85% Vespel, 15% Graphite Long Ferrules (for GC/MS)	0.4	0.1, 0.2, 0.25	5062-3508
	0.5	0.325062-3506
	0.8	>0.53	5062-3538
100% Vespel Short Ferrules (for isothermal analysis only)	0.4	0.1, 0.2, 0.25	5181-3322
	0.5	0.32	5062-3513
	0.8	0.45, 0.53	5062-3511
UltiMetal Plus Flexible Metal Ferrules	0.4	0.1-0.25	G3188-27501
	0.5	0.32	G3188-27502
	0.8	0.45-0.53	G3188-27503
	0.5	0.25-.032 UltiMetal tubing	G3188-27505
	0.8	0.53 UltiMetal tubing	G3188-27506

 

 

5. Using Pre-conditioned Ferrules for Improved Sensitivity
 
When background noise is reduced, overall sensitivity improves. Using GC and GC/MS ferrules of appropriate material and dimensions reduces any contribution the ferrules may have on the level of background noise. Graphite/Polyimide ferrules that are properly pre-conditioned provide the best opportunity to achieve optimum sensitivity. Pre-conditioning these ferrules reduces the potential for bleed from the ferrules.
 
UltiMetal Plus deactivation on the surface of Flexible Metal ferrules improves analysis of active analytes by providing a more completely inert flow path.  The chemical deactivation provides inert surface for analysis of active analytes at trace levels.  These were designed for Capillary Flow Technology devices, but also suitable for inlet and detector connections.  These ferrules can be permanently pre-swaged onto the capillary tubing for better control and consistency of the measured length of column installed into the inlet or detector fitting.

6. Deciding Between Long or Short Ferrules
 
Short ferrules, and accompanying column nuts, are the preferred choice for typical detector and inlet configurations on Agilent GCs.  Combined with the Self Tightening column nut (5190-6194), short graphite/polyimide blend ferrules provide a robust leak free seal, without concerns associated with graphite ferrules, at the inlet and oxygen sensitive detectors, like the ECD.   Short graphite ferrules are ideal for applications using the FID or NPD, using the universal column nut (5181-8830).
 
Long ferrules were traditionally used for the detector connection when using an MS detector because of the nut and interface design.   The MS interface nut (05988 -20066) is used with pre-conditioned long graphite/polyimide blend ferrules on the MS end of the column.  Agilent offers a special inlet nut (05921-21170) that allows the use of the same long ferrules for both inlet and detector on MSD systems.
 
When using the Self Tightening column nuts (5190-6194 for the inlet / 5190-5233 for MSD), a single set of short graphite/polyimide blend ferrules may be used for both the inlet and detector ends of the column.