Department of Chemistry, University of Nairobi, Nairobi, Kenya
Research Article
Effect of Incandescent and Fluorescence Bulb on Pentachlorophenol and
Di-methoate on Spinach Leaf Surface
Author(s): Antony Kinyua*, James Kamau Mbugua, Gabriel A Waswa and Joyce GN Kithure
Photo-degradation of pentachlorophenol and Di-methoate on spinach leaf surface by incandescent and a fluorescence
bulb was investigated. The study involved, spraying the standard pesticide solutions on 5 cm-by-5 cm spinach leaf
obtained from Negara market before exposing to 40 W, 60 W, 75 W and 100 W incandescent bulbs and 9 W, 11 W,
15 W and 20 W fluorescence tube for 10, 20, 30, 60 and 120 minutes. The remaining residues level after exposure
was determined by Shimadzu UV-Visible spectrophotometer at 322 nm and 229 nm for Pentachlorophenol and
Di-methoate respectively.
The results obtained indicate that the photo-degradation of pesticide residue depends on light intensity, temperature,
pesticide molecular structure and time of exposure. The rate constant ranged from 0.0091 to 0.0116 for Di-methoate
and 0.046 to 0.069 for pentachlorophenol. The rate of deg.. View more»