Chapter-24-Notes

Chapter-24-Notes - 95C, He, 34 cm/s GC and LC with chiral...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Ch. 24 Gas Chromatography (GC) For volatile liquid or gaseous solutes Solute is carried by a gaseous mobile phase over a stationary phase on the inside of an open tubular column or on a solid support High-Performance Liquid Chromatography (HPLC) For compounds not sufficiently volatile for GC Solvent is pumped at high pressure through a column containing stationary-phase 3-10 um-dia. particles (e.g., silica) with covalently bonded liquid phase (e.g., octadecyl, C 18 ) 1 2 GC Columns 3 4 The choice of liquid stationary phase is based on the rule “like dissolves like” e.g., Nonpolar columns are best for nonpolar solutes
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
GC of vapors in the headspace of a beer can using a 0.25-mm-diameter × 30-m- long porous carbon column at 30°C for 2 min and then ramped up to 160°C at 20°/min.
Background image of page 2
Resolution N 1/2 L 1/2 . 1) 1,3-dichlorobenzene 2) 1,4-dichlorobenzene 3) sec-butylbenzene 4) 1,2-dichlorobenzene DB-1 stationary phase with 0.25- µ m layer, 0.32-mm diameter,
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 95C, He, 34 cm/s GC and LC with chiral phases can separate -very few other methods can optical isomers (enantiomers) 5 6 Zeolite molecular sieves Aluminosilicate minerals with framework interconnections that produce a cavity into which small molecules can enter Influence of polarity of stationary phase on relative retention times 7 8 Polar Nonpolar Temperature and Pressure Programming 9 10 Injection into open tubular columns in GC 11 12 Effects of operating parameters in split and splitless injections Routine for introducing small sample volume Best for trace levels of high-boiling solutes in low-boiling solvents Best for quantitative analysis; best for thermally unstable solutes and high-boiling solvents Detectors in GC 13 14 GC analysis of natural gas -importance of the type of detector 15 16 GC-MS (mass spectroscopy detector) Flame ionization detector Sulfur chemiluminescence detector...
View Full Document

This note was uploaded on 10/26/2008 for the course CHEM 300L taught by Professor Flood,haw during the Fall '08 term at USC.

Page1 / 6

Chapter-24-Notes - 95C, He, 34 cm/s GC and LC with chiral...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online