Liquid chromatography-flame ionisation detection using a nebuliser/spray chamber interface. Part 1. Design and...

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Flame ionisation detectors (FID) are widely used in gas chromatography.
• Adapting FID for liquid chromatography (LC) presents challenges due to solvent and analyte volatility.

Purpose of the Study:

• To develop and evaluate a system for interfacing flow injection analysis (FIA) with a flame ionisation detector (FID) for use as a universal detector in liquid chromatography (LC).
• To assess the detector's response to a wide range of analytes, including volatile and involatile compounds with and without chromophores.

Main Methods:

• Utilized a nebuliser and spray chamber to couple a flow injection analyser (FIA) system to a flame ionisation detector (FID).
• Optimized hydrogen and air flow rates to ensure system stability.
• Investigated the detector's response to various analyte classes, including alkanes, alkanols, aromatic amides and acids, phenols, amino-acids, and carbohydrates.
• Examined the necessity of adding acid or salt to the carrier stream for involatile polar analytes.

Main Results:

• The FIA-FID system demonstrated a response to both volatile and involatile analytes, irrespective of chromophores.
• A linear response was observed for many tested analytes.
• Addition of trace amounts of acid or salt to the carrier stream was required to achieve a linear response for involatile polar analytes.

Conclusions:

• The nebuliser-spray chamber interface effectively links FIA to FID, offering potential as a universal detector for LC.
• The system shows broad applicability for detecting diverse chemical compounds.
• Methodological adjustments are necessary for optimal quantification of specific analyte types, particularly involatile polar compounds.