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Tallahassee, FL, United States

A single-laboratory validation study was conducted for the simultaneous determination of arsenic, cadmium, calcium, cobalt, copper, chromium, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in all major types of commercial fertilizer products by microwave digestion and inductively coupled plasma-optical emission spectroscopy analysis. This validation study proposes an extension and modification of AOAC 2006.03. The extension is the inclusion of calcium, copper, iron, magnesium, manganese, and zinc, and the modification is incorporation of hydrochloric acid in the digestion system. This dual acid digestion utilizes both hydrochloric and nitric acids in a 3 to 9 mL volume ratio/100 mL. In addition to 15 of the 30 original validation materials used in the 2006.03 collaborative study, National Institute of Standards and Technology Standard Reference Material 695 and Magruder 2009-06 were incorporated as accuracy materials. The main benefits of this proposed method are a significant increase in laboratory efficiency when compared to the use of both AOAC Methods 965.09 and 2006.03 to achieve the same objective and an enhanced recovery of several metals.

Eitzer B.D.,U.S. Department of Soil and Water | Hammack W.,125 Conner Blvd | Filigenzi M.,University of California at Davis
Journal of Agricultural and Food Chemistry | Year: 2014

An interlaboratory comparison of a multipesticide residue analytical method is reported. The goal of the comparison was to evaluate the potential for liquid chromatography/high resolution mass spectrometry along with a specific automated screening procedure to allow the determination of the presence or absence of a set of targeted compounds without additional manual review. The method utilized an off the shelf QuEChERs based extraction followed by analysis with an orbitrap mass spectrometer with the data evaluated by ToxID. The method was tested at three laboratories, with three produce matrices (spinach, carrots, and oranges), and three levels of spiked pesticides with all analyses in triplicate. A series of 247 compounds were tested, and it was found that the three laboratories produced consistent data; however, manual review was still necessary. The data was shown to have no false negatives for 211 compounds in the three produce matrixes at 200 ppb. Of these 211 compounds, 189 had no false negatives at 50 ppb, and 129 had no false negatives at 10 ppb. The HRMS method was shown to be robust with similar data being achieved by all three laboratories and detectable concentrations only slightly above the range shown for triple quadrupole MS/MS. © 2013 American Chemical Society.

Feken M.,125 Conner Blvd | Johnson J.,600 E. Blvd.
ACS Symposium Series | Year: 2012

As "co-regulators" with the U.S. Environmental Protection Agency (EPA) under FIFRA, state pesticide regulatory agencies (SPRAs) have primary responsibility to enforce both federal and state pesticide laws. SPRAs and the pesticide stakeholders they regulate are particularly concerned about uncertainties in the implementation process of the Endangered Species Act (ESA) at the national level and potential obstacles for stakeholders to participate in the development of mitigation measures that are reasonable and enforceable. This paper identifies areas where SPRAs can assist EPA to be in compliance with the ESA. Examples are given on data the SPRAs can provide to assist EPA in determining risk and developing endangered species effects determinations. © 2012 American Chemical Society.

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