September 2018

Spectrophotmetric evaluation of rotenone extraction from leaves and seeds of mature Tephrosia vogelii plant

The percentage yield of rotenone extracted from Tephrosia vogelii leaves and seeds was investigated.  Ten samples of well ground leaves and seeds were each subjected to extraction in soxhlet extraction system using trichloromethane, ethanol and methanol solvents for 24 h at room temperature. The maximum absorption wavelength of rotenone was determined using Ultra violet-visible spectrophotometer.  Different...

Author(s): Kariuki, D. K. and Njiru, S. N.  

September 2018

Preliminary characterization of some natural dyes

A preliminary study on the chemical structure of dyes from Rothmannia hispidia, Pterocarpus osun and Terminalia superba was made using chemical tests, UV-visible and infrared spectroscopies. R. hispidia dye was found to contain an alkyl amino group (-NHR) and carbon-carbon double bond conjugated with a carbonyl (C = O) group, and also showed maximum absorption at 595 nm in the visible region. P. osun dye contains...

Author(s): Mercy Amarachukwu Ezeokonkwo, Sunday Nwankwo Okafor and Evelyn Uloma Godwin-Nwakwasi