Wednesday, November 15, 2006
280-4
Spectrophotometric Determination of Zinc in Plant, Soil, and Fertilizer Samples.
Sarah Johnson, Jack D.C. Jacob, and Roland J. Buresh. IRRI, DAPO Box 7777, DAPO Box 7777, Metro Manilla, PHILIPPINES
Zinc deficiency is one of the most common micronutrient constraints to rice production leading to poor plant growth and low grain yields. To determine the effects of crop management practices on zinc nutrition in rice plants, there is a need for a quick and inexpensive quantitative analysis for zinc in plant, soil and fertilizers. Plant, soil and fertilizer samples were extracted for zinc using the most commonly used methods and analyzed spectrophotometrically. The samples were also analyzed using atomic absorption spectroscopy (AAS) for comparison. Masking agents, complexing agents, and chemical purification were used to counter the effect of interfering ions. Provided that the pH of each matrix is properly adjusted and the effect of interfering ions are removed before analysis, spectrophotometric analyses of zinc can produce results comparable with those of AAS and could be used as a more affordable alternative.