Retention gaps

Precolumns and retention gaps
Features

Retention gaps
	The retention gap technique in combination with on-column injection allows concentration of a large sample volume in the capillary column.
	Choice of the retention gap depends on the solvent used: the flooded zone after injection should be between 20–30 cm/µL
	Me-Sil retention gap	only for use with n-hexane and diethyl ether
	Phe-Sil retention gap	for all solvents except methanol and water
	CW retention gap	for all solvents and especially for methanol and water
	Calculation example: length of flooded zone ~ 20–30 cm/µL, retention gap 10 m x 0.32 mm ID, capillary column: 25 m x 0.32 mm ID, max. injection volume ~ 30–50 μL
	A retention gap must be inert without any noticeable retention. Me-Sil retention gaps are more inert than Phe-Sil, while Phe-Sil is less susceptible to contamination.
	Max. temperatures: for CW retention gaps 250 °C, for Me-Sil and Phe-Sil retention gaps 320 °C
	Retention gaps can also be used as transfer lines or precolumns (contamination capacity about 5–10 µg).

Deactivated capillary columns (precolumns)
	Recommended application: for preparation of capillary columns as precolumns, whenever a larger contamination capacity is required.

Untreated capillaries
	Recommended application: for capillary electrophoresis ∙ for preparation of capillary columns ∙ for capillary LC applications

Ordering information
Length ->	1 m (pack of 3)	10 m (pack of 1)	25 m (pack of 1)
Retention gaps
Me-Sil retention gaps (max. temperature 320 °C)
0.25 mm ID (0.4 mm OD)		723706.10	723706.25
0.32 mm ID (0.5 mm OD)		723707.10	723707.25
0.53 mm ID (0.8 mm OD)		723708.10	723708.25
Phe-Sil retention gaps (max. temperature 320 °C)
0.25 mm ID (0.4 mm OD)		723709.10	723709.25
0.32 mm ID (0.5 mm OD)		723710.10	723710.25
0.53 mm ID (0.8 mm OD)		723711.10	723711.25
CW retention gaps (max. temperature 250 °C)
0.25 mm ID (0.4 mm OD)		723712.10	723712.25
0.32 mm ID (0.5 mm OD)		723713.10	723713.25
0.53 mm ID (0.8 mm OD)		723714.10	723714.25
Deactivated capillary columns (precolumns)
Methyl-Sil deactivated (max. temperature 320 °C)
0.25 mm ID (0.4 mm OD)		723106.10	723106.25
0.32 mm ID (0.5 mm OD)		723346.10	723346.25
0.53 mm ID (0.8 mm OD)		723558.10	723558.25
Phenyl-Sil deactivated (max. temperature 320 °C)
0.25 mm ID (0.4 mm OD)		723108.10	723108.25
0.32 mm ID (0.5 mm OD)		723348.10	723348.25
0.53 mm ID (0.8 mm OD)		723560.10	723560.25
CW deactivated (max. temperature 25 °C)
0.25 mm ID (0.4 mm OD)		723105.10	723105.25
0.32 mm ID (0.5 mm OD)		723349.10	723349.25
0.53 mm ID (0.8 mm OD)		723562.10	723562.25
Untreated capillaries
Capillaries for electrophoresis
0.025 mm ID (0.4 mm OD)	723793.1	723793.2
0.05 mm ID (0.4 mm OD)	723790.1	723790.2
0.075 mm ID (0.4 mm OD)	723791.1	723791.2
0.10 mm ID (0.4 mm OD)	723792.1	723792.2
Untreated capillaries
0.20 mm ID (0.4 mm OD)		723148.10	723148.25
0.25 mm ID (0.4 mm OD)		723101.10	723101.25
0.32 mm ID (0.5 mm OD)		723151.10	723151.25
0.53 mm ID (0.8 mm OD)		723501.10	723501.25
Retention gaps, deactivated and untreated capillaries are supplied without cage.