Enhancement of sensitivity in capillary supercritical fluid chromatography through optimization of injection and detection techniques

✍ Scribed by Munder, A. ;Chesler, S. N.

• Book ID: 102894351
• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 561 KB
• Volume: 12
• Category: Article
• ISSN: 0935-6304
• DOI: 10.1002/jhrc.1240121008

✦ Synopsis

The reproducibility of peak areas as a function of the technique used for sample injection was investigated in capillary supercritical fluid chromatography (SFC). An injection technique has

been developed to increase the volume of sample introduced into the capillary column. Using a modified time-split injection technique,long injection duration timeswere successfullyapplied to achieve lower detection limits. Analytes were effectively focused at the head ofthe analytical column using a unique pressure trap program. Because this on-column focusing was performed only by pressure and temperature programming, no instrumental modifications were necessary. Up to 1 .O pLof sample solution was injected onto 50 pm i.d.columns usingthistechnique, with no observable peak splitting. Dual detection using ultraviolet (UV) absorption and flame ionization detection (FID) was performed in series, thereby avoiding the necessityof splitting the column effluent. For the compounds investigated (five nitroaromatics and one phthalate ester), the absolute sensitivity of the UVdetector was significantly greater than that of the FID.

Certain commercial equipment, instruments or materials are identified in this report to specify adequately the experimental procedure Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identihed are necessarily the best available for the purpose Ms