A Validated Headspace Gas Chromatographic Method for the Determination of Ethyl Alcohol in Food Supplements

Food supplements are defined as products containing nutritional elements such as vitamins, minerals, amino acids, and herbal components that cannot be taken in adequate amounts with normal nutrition. Ethyl alcohol (EtOH) is used in the production and standardization of some food supplements. Even a little MeOH can cause serious health problems in EtOH. Authorized institutions issuing halal product certificates consider foods containing more than 1% alcohol to be haram. In this study, new, reliable, sensitive, and fast GC-FID and HS GC-FID methods were developed, validated, and compared to determine the amount of EtOH and MeOH that can be found in food supplements. Chromatographic separation was performed with DB-WAX (30 m × 0.32 mm × 0.5 μm) and TC-WAX (30 m × 0.32 mm × 0.5 μm) in the GC-FID and HS GCFID methods, respectively. Oven temperature program that increased 5°C/min from 80°C to 100°C in 40:1 split condition was used. The calibration range is 0.002–0.1 g/dL. LOD and LOQ values are found as 0.00036 and 0.00050 g/dL and 0.0011 and 0.0015 g/dL for EtOH and 0.00050 and 0.00060 g/dL and 0.0015 and 0.0019 g/dL for MeOH by GC-FID and HS GC-FID methods, respectively. The developed and validated methods were applied to different food supplements commercially sold in the market with the label containing alcohol but not containing alcohol percentage and one food supplement with the label alcohol-free. The developed and validated GC-FID and HS GC-FID methods can be used in the determination of EtOH and MeOH in food supplements.