WAC 16-200-7062   What method must I use to analyze the total metals contained in my commercial fertilizer?  (1) You must prepare your sample of commercial fertilizer using U.S. Environmental Protection Agency ("EPA") sample preparation method 3050B (except when preparing a sample for analysis of mercury*). You must analyze your commercial fertilizer for the total concentration of each of the following nine metals in each commercial fertilizer using one or more of the EPA analysis methods listed in Table 1. All methods are described in EPA's SW-846, Third Edition.


    
Table 1. Acceptable Sample Preparation and Analysis Methods for Total Metals

Metal	Inductively Coupled Plasma (ICP)	Atomic Absorption	Inductively Coupled Plasma Mass Spectroscopy (ICP/MS)
Arsenic (As)	6010, 6010A, 6010B	7060A, 7061A	6020
Cadmium (Cd)	6010, 6010A, 6010B	7131A	6020
Cobalt (Co)	6010, 6010A, 6010B	7201	6020
Lead (Pb)	6010, 6010A, 6010B	7420, 7421	6020
Molybdenum (Mo)	6010, 6010A, 6010B	7480	6020
Nickel (Ni)	6010, 6010A, 6010B	7520, 7521	6020
Selenium (Se)	6010, 6010A, 6010B	7740, 7741A	6020
Zinc (Zn)	6010, 6010A, 6010B	7951	6020
Mercury (Hg)		7470A*, 7471A*
Sample Preparation	3050B	3050B	3050B

Copies of SW-846 Third Edition and all associated updates are available from: The Government Printing Office, Superintendent of Documents, Washington, DC 20402, (202) 512-1800, and from the Department of Commerce, National Technical Information Center, 5285 Port Royal Road, Springfield, VA 22161, (703) 487-4650 or 800-553-NTIS.


*Since sample preparation method 3050B cannot provide for an analysis of mercury, when you prepare a sample for analysis of mercury you must use the sample preparation method established for analysis method 7470A when using method 7470A to analyze your sample and the sample preparation method established for analysis method 7471A when using method 7471A to analyze your product.


     (2) Other sample preparation and analysis methods for total concentration of each metal in each commercial fertilizer may be used only under the following conditions:

     (a) You must submit a request to the department, in writing, detailing the sample preparation and analysis methods, minimum detection limits and quality assurance, quality control documentation and a side-by-side comparison of the analysis results from the alternative method to one of the approved methods' analysis results of the same material; and

     (b) The department, after reviewing the request, may approve the sample preparation or analysis method only if the capability of the method meets or exceeds the sensitivity and accuracy of the applicable method listed in the Table 1.

     (3) Any commercial fertilizer product registered prior to the enactment of these provisions using any sample preparation or analysis method not authorized by subsection (1) or (2) must be registered in accordance with subsection (1) or (2) in the next annual commercial fertilizer registration cycle.



[Statutory Authority: Chapter 15.54 RCW. 99-02-035, § 16-200-7062, filed 12/30/98, effective 1/30/99.]