capillary columns nicholas h. snow department of chemistry, seton hall university, 400 south orange...
Post on 21-Dec-2015
218 views
TRANSCRIPT
Capillary Columns
Nicholas H. Snow
Department of Chemistry, Seton Hall University, 400 South Orange Avenue, South Orange, NJ
07079
Tubing Material
• Stainless Steel– reactive
• Glass– can be made inert– difficult to handle
• Fused Silica– flexible– most inert– most popular
Stationary Phase Film Thickness
• Starting point: 0.25m• Compromise: resolution and
capacity• Practical operating
temperatures• Speed or resolution
Thick Film Stationary Phase
• Advantages– increased retention for
volatiles
– increased capacity
• Disadvantages– less efficient
– higher temperatures
– higher bleed
Thin Film Stationary Phase
• Advantages– high efficiency
– lower elution temperatures
– fast analysis
• Disadvantages– low capacity
– limited trace analysis