Determination of some organochlorine compounds in herbal colouring agent henna (Lawsonia inermis) and in tea (Thea sinensis).

Henna (Lawsonia inermis) has been used for centuries as a herbal hair and skin dye, but very little is known about its additives and contaminants that could adversely affect human health. An analytical method was developed to determine organochlorine compounds in henna, as they are still widely used in the areas where henna is grown. Samples were sonicated with n-hexane, extracts cleansed on Florisil sorbent and analysed using gas chromatography with electron capture detection. The overall recoveries were 17-33 % with the extraction RSD 5-21%, while the levels of lindane (gamma-HCH), p,p'-DDT, and p,p'-DDE in henna samples were 7-157 microg kg(-1). The same procedure was successfully applied to analyse black tea samples for the same compounds, and which showed lower contamination.