Chemical characterization and antimicrobial potential of purified aceh patchouli oil (Pogostemon cablin Benth.) residue for floor cleaning product innovation

• Patchouli oil residue was characterized using GC-MS and found rich in patchouli alcohol. • Iron content in the residue was reduced by 60.7% using activated charcoal. • The residue showed antibacterial and antifungal activity against S. aureus, E. coli , and C. albicans . • A floor cleaning soap was formulated and met Indonesian National Standard (SNI 1842:2019). • The formulated product retained strong antimicrobial activity against tested microbes. Patchouli oil residue, a by-product of vacuum distillation, remains underutilized despite its bioactive compound content. This study aimed to characterize the residue using Gas Chromatography–Mass Spectrometry (GC-MS), purify iron (Fe) contamination using activated carbon, evaluate its antimicrobial and antifungal activities, and formulate it into a floor-cleaning soap. GC-MS analysis identified patchouli alcohol (57.19%) as the dominant compound. Purification using 5 g of activated carbon for 3 hours reduced Fe content from 10.351 mg/L to 4.062 mg/L (60.7% reduction), improved residue clarity, and eliminated naphthalene, a potential contaminant. The purified residue exhibited strong antibacterial activity against Staphylococcus aureus (13.28 mm ± 1.38) and moderate activity against Escherichia coli (7.02 mm ± 0.23), as well as strong antifungal activity against Candida albicans (14.88 mm ± 2.88). The formulated floor-cleaning soap met Indonesian National Standard (SNI 1842:2019) for pH, viscosity, specific gravity, foam stability, and homogeneity. It retained bioactivity with inhibition zones of 15.89 mm ( S. aureus ), 6.00 mm ( E. coli ), and 10.89 mm ( C. albicans ), showing enhanced antibacterial activity against S. aureus compared to the purified residue, but slightly lower activity against E. coli and C. albicans . These findings confirm that the formulated product not only meets national standards but also offers antimicrobial functionality. This study contributes a sustainable and scientific approach to valorizing agro-industrial waste into a value-added floor-cleaning product with confirmed antimicrobial and antifungal efficacy, aligning with green chemistry and circular economy principles.