Validation and analysis of diallyl disulfide and diallyl trisulfide in garlic (Allium Sativum L.) using gas chromatography

Objective: The purpose of this research was to optimize and validate a method for measuring the levels of diallyl disulfide (DADS) and diallyl trisulfide (DATS) in garlic and single clove garlic. Methods: The analysis was performed using gas chromatography (GC) equipped with an HP-1 column and a flame ionization detector. The initial column temperature was set at 140°C and increased at 1°C/min to 180°C. The injector and detector temperatures were set to 200°C, the carrier gas flow rate was 0.80 mL/min, and the injection volume was 1.0 nL. The optimized conditions of analysis were then validated which included selectivity, linearity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Results: Using the validated assay and a concentration range of 0.5-20 ng/mL, the coefficient of correlation (r) for DADS was 0.9999 and the LOD and LOQ for DADS were 0.3063 ng/mL and 1.0210 ng/mL, respectively. Using the validated assay and a concentration range of 0.5-20 ng/mL, the coefficient of correlation for DATS was 0.9999 and the LOD and LOQ for DATS were 0.1986 ng/mL and 0.6621 ng/mL, respectively. The percentage of recovery was in the range of 98.05-101.76% and coefficient of variation < 2%. Conclusion: This GC method accurately measures the levels of DADS and DATS in garlic.