Determination of iodopropynyl butylcarbamate in cosmetic formulations utilizing pulsed splitless injection, gas chromatography with electron capture detector

- Iodopropynyl butylcarbamate (IPBC) preservative analysis using gas chromatography with electron capture detector (GC-ECD).
- Pulsed injection technique overcomes the thermal liability of IPBC enabling selective analysis by GC-ECD in complex cosmetic products.
- The methodology is robust (RSD 4%), accurate (98% recovery), and sensitive (LOD 0.25 ng/ml) for routine testing of formulation preservation.

Current analytical methodology for iodopropynyl butylcarbamate (IPBC) analysis focuses on the use of liquid chromatography and mass spectrometer (LC-MS), but the high instrumentation and operator investment required has resulted in the need for a cost effective alternative methodology. Past publications investigating gas chromatography with electron capture detector (GC-ECD) for IPBC quantitation proved largely unsuccessful, likely due to the preservatives limited thermal stability. The use of pulsed injection techniques commonly used for trace analysis of thermally labile pharmaceutical compounds was successfully adapted for IPBC analysis and utilizes the selectivity of GC-ECD analysis. System optimization and sample preparation improvements resulted in substantial performance and reproducibility gains. Cosmetic formulations preserved with IPBC (50-100 ppm) were solvated in toluene/isopropyl alcohol and quantified over the 0.3-1.3 μg/ml calibration range. The methodology was robust (relative standard deviation 4%), accurate (98% recovery), and sensitive (limit of detection 0.25 ng/ml) for use in routine testing of cosmetic formulation preservation.