Screening method for ethylene glycol and diethylene glycol in glycerin-containing products

This paper describes a capillary gas chromatographic method with flame ionization detection for the identification/quantification of ethylene glycol (EG) and diethylene glycol (DEG) in glycerin. The validation study shows that the proposed method is specific, sensitive, precise, and accurate. The linear range of the method was 0.013-0.031mg/mL for EG and 0.012-0.030mg/mL for DEG. Wider ranges may be achievable but were not investigated. The limit of detection of EG and DEG were determined as 0.0018% and 0.0036% (w/w) respectively, and at this concentration the signal-to-noise ratios for EG and DEG were approximately 3:1. The method was also used to determine EG and DEG in toothpaste. The results were compared to those obtained by thin-layer chromatography (TLC) and showed greater sensitivity and specificity.