Determination of Para-Phenylenediamine (PPD) in Henna Samples Collected from Libyan Local Markets Using HPLC

Henna is frequently used as body adornment in Libya, the Arabic world, and some African and Asian countries. It is part of the traditions and cultures. The addition of para-phenylenediamine (PPD) to the natural henna increases the risk of allergic contact dermatitis as well as toxic effects, which sometimes lead to severe toxicity and death. Cases have already been reported in Al-Bayda city - Libya. This study aimed to identify the presence and determination of PPD in henna by High-Performance Liquid Chromatography (HPLC). In the current study, eleven henna samples were collected from local markets in Al-Bayda - Libya. A rapid, simple, and reliable method is developed and validated for the determination of PPD in henna samples using 50% methanol solution as solvent. The method is validated over a wide linear range of 5 – 25 µg/ml with correlation coefficients being consistently greater than 0.997. The minimum PPD level was observed in a random sample of mixed henna (paste2) (0.0104 % w/w), while the Royal Black Henna sample showed the highest PPD content (11.9107 % w/w). The HPLC measurements indicated that the results of PPD concentrations in the Royal Red henna sample and Shikha henna (natural henna) were PPD free (ND) (Not Detected). The concentrations in Black henna samples were higher than Red henna samples. The PPD content in red henna samples analyzed in this study is below the allowable limits set by the Scientific Committee on Consumer Products (SCCP) and the US Food and Drugs Administration. While in Black henna samples it was higher than that recommended limit.