Document Abstract
A sensitive analytical procedure based on solid phase extractive-spectrophotometry
has been established for the determination of the widely used herbicide
atrazine .The method is based on the Konig reaction in which atrazine reacts
with pyridine reagent to form a quaternary pyridinium halide, which further forms
glutaconic aldehyde in the presence of alkali. Glutaconic aldehyde is subsequently
coupled with 4-aminoacetanilide in the micellar medium of anionic surfactant
sodium dodecyl sulphate to give a yellow-orange dye. The produced dye was
enriched on a C18 cartridge and is measured spectrophotometrically at 460 nm. The
sensitivity and selectivity of the method was largely enhanced in the micellar media
and SPE on the C18 cartridge and avoids the use of toxic solvents. Beer’s law was
obeyed in the range 0.012–0.12 lg mL-1. Molar absorptivity and Sandell’s sensitivity
were found to be 1.52 9 106 L mol- 1 cm-1 and 0.0002 lg cm-2, respectively.
The limit of detection and quantification were 0.001 and 0.003 lg mL-1,
respectively. The proposed method was applied successfully for the determination
of atrazine in environmental and biological samples with a recovery range of
96–101 %. The method was found to be free from interference of a large number of
foreign species. The accuracy and reliability of the method was further established
by parallel determination by the reference method, and by recovery studies.