Glycols & Glycerine

Importance of the topic

Accurate analysis of glycols and glycerine is critical in pharmaceutical, food, cosmetic and industrial quality control. These polar compounds often interact with active sites of gas chromatographic systems, leading to peak tailing and poor reproducibility. An inert GC phase and optimized method enable rapid, reliable determination of ethylene glycol, propylene glycol, diethylene glycol and glycerine, supporting compliance with regulatory standards and ensuring product safety.

Study objectives and overview

The primary goal was to develop and demonstrate a robust GC-FID method for simultaneous separation and quantification of four common glycols and glycerine using an InertCap® 1701 column. The study evaluated chromatographic performance, peak shape, resolution and analysis time under specified operating conditions.

Methodology and instrumentation

Sample preparation involved dissolving analytes at 500 μg/mL in methanol. The GC method parameters were:

• Column: InertCap® 1701, 0.32 mm I.D. × 30 m, film thickness 1.0 µm
• Oven program: 100 °C hold for 5 min, ramp 7.5 °C/min to 220 °C
• Carrier gas: Helium at 100 kPa
• Injection: Split, 1 µL, split flow 53.6 mL/min, injector at 220 °C
• Detection: Flame ionization detector at 250 °C, range 10⁰

Used instrumentation

• Gas chromatograph with FID (GL Sciences Inc.)
• InertCap® 1701 capillary column (Catalog No. 1010-61245)

Main results and discussion

All four compounds were baseline resolved within 8 minutes. Ethylene glycol eluted first, followed by propylene glycol, diethylene glycol and glycerine. The inert surface of the column minimized adsorption of hydroxyl-rich compounds, yielding symmetrical peaks and consistent retention times. The FID response was linear for all analytes at the tested concentration.

Benefits and practical applications

• Fast throughput with total run time under 10 minutes
• Excellent peak shapes and reproducibility for polar analytes
• Simple sample preparation compatible with routine QC laboratories
• Applicable to regulatory compliance testing in pharmaceutical, food and cosmetic industries

Future trends and opportunities

Integration with mass spectrometry detection can enhance selectivity and sensitivity, enabling trace-level quantification in complex matrices. Two-dimensional GC and online derivatization techniques may further improve separation of higher glycols and related impurities. Advances in column technology and green carrier gases will support more sustainable and high-throughput workflows.

Conclusion

The presented GC-FID method using an inert 1701 phase delivers reliable, fast and reproducible analysis of glycols and glycerine. Its robustness and ease of operation make it well suited for diverse quality control and research applications.

Reference

Data No. GA100-0875