Date of Award
Spring 6-2026
Document Type
Thesis
Degree Name
Master of Science (MS)
Department/Program
Forensic Science
Language
English
First Advisor or Mentor
Angelique Corthals
Second Reader
Michelle D. Miranda
Third Advisor
Anna Duggar
Abstract
Henna, a natural dye derived from Lawsonia inermis, is widely used for temporary body art, hair coloring, and cultural decorative practices such as Mehendi. Traditional henna produces a reddish-brown stain through lawsone, a naphthoquinone chromophore that binds to keratin in skin, hair, and nails (Badoni Semwal et al., 2014; de Groot, 2013; Kumar Singh et al., 2015). Commercial henna products have increasingly incorporated synthetic dyes, pigments, and glitter additives to produce a broader range of colors and effects (Blair et al., 2004; Manso et al., 2017; Blackledge & Jones, 2007). Despite their prevalence, limited forensic research has examined the chemical variability of these products and their potential evidentiary value.
This study characterized and compared the chemical, morphological, optical, and elemental composition of commercially available henna products using polarized light microscopy (PLM), ultraviolet-visible (UV/Vis) spectrophotometry, attenuated total reflectance infrared spectroscopy (ATR-IR), solvent-based extraction methods, and X-ray fluorescence spectroscopy (XRF). PLM identified plant-derived fibrous material, pigment particles, and glitter fragments in modified formulations. UV/Vis analysis revealed strong visible absorption maxima between approximately 480–670 nm in colored samples, indicating additional chromophores beyond natural lawsone (Nair et al., 2024; Okoye et al., 2021). ATR-IR and XRF analyses further demonstrated variability in synthetic additives and inorganic components across brands and formulations.
The findings demonstrate substantial compositional differences among commercial henna products and support the forensic utility of multi-instrumental analytical approaches for distinguishing henna-based trace materials (Schotman et al., 2017; Smith et al., 2021).
Recommended Citation
Bhagwandeen, Vani D., "The Comparative Chemical Analysis of Colored Henna" (2026). CUNY Academic Works.
https://academicworks.cuny.edu/jj_etds/391
