June 4 - 6, 2012
Crowne Plaza Hotel
St. Louis, MO
Fertilizer, Session Chair: Dr. Sharon Webb
- RHONDA BOLES, Experiment Station Chemical Laboratories, Agriculture Experiment Station, University of Missouri- Columbia, Columbia, MO, USA
Analysis of Calcium, Copper, Iron, Magnesium, Manganese, and Zinc in fertilizers by Atomic Absorption Spectrophotometry in a modification of the
microwave sample preparation in AOAC OMA 2006.03
The test solutions in AOAC OMA 965.09, Nutrients (Minor) in Fertilizers Atomic Absorption Spectrophotometric Method are prepared using a hotplate or a combination
of a hot plate and a muffle furnace. The acids used in the extraction include hydrochloric acid, perchloric acid and hydrofluoric acid. Few laboratories have access to
the hood required to employ perchloric acid in digestions. The sample digestion performed in AOAC OMA 2006.03 uses a microwave and nitric acid. The modification
tested in this work was the use of 9 mL nitric acid with 3 mL of hydrochloric acid instead of 10 mL nitric acid. Magruder Check Samples from 2009 to 2012 were
extracted using OMA 965.09 C.(a) and the proposed modification of 2006.03. Detection was performed by Atomic Absorption Spectrophotometry.
RHONDA BOLES, Supervisor, Agriculture Fertilizer Laboratories, Experiment Station Chemical Laboratory, University of Missouri- Columbia, Agriculture Building,
Room 4, Columbia, MO 65211 USA; phone: (573)882-2608 email: BolesR@Missouri.edu.