A Rapid Bioassay for Simultaneous Identification and Quantitation of Picloram in Aqueous Solution
FORT DETRICK FREDERICK MD
Pagination or Media Count:
A simple bioassay technique is described that offers a rapid and sensitive means for the simultaneous detection and quantitative determination of picloram 4-amino-3, 5,6-trichloropicolinic acid in micro-quantities of aqueous solution. When lettuce seed were placed on small squares of filter paper moistened with picloram solutions, the concentration of picloram was related to the degree of growth inhibition of root and hypocotyl elongation 72 hours after initiation of the test. Inhibition was a useful parameter in determining quantities of picloram ranging from 0.036 micro to 7.2 micro. After paper chromatographing plant exudates containing C14-labeled picloram, location and quantities of picloram on the chromatograms were determined by the lettuce bioassay and compared with determinations by the methods of UV light sensitivity, C14 4 pi strip scanning, and C14 dilution calculations. Rf values determined by all methods were identical, and the quantitative determination by the bioassay agreed closely with calculations based on the amount of C14 detected by liquid scintillation counting.