October 26, 1999

Dear Laboratory Director:

Attached are results from the recent Florida Mercury Intercomparison Study, FMIP-0999 (Attachment 1). A list of participating laboratories and associated contacts are included in Attachment 2.

A single surface water sample from site U3 in Water Conservation Area 2A of the Florida Everglades was used for this study. Paul Parks of the Florida Department of Environmental Protection (FDEP) Mercury Coordinator’s Office collected the sample on September 9. Using a Nytex filter on the suction side of the sampling pump, aliquots were collected into three new Nalgene LDPE 20L bottles with screw tops. Samples were stored in coolers without ice or any additional preservation.

Sample bottles were transported to Tallahassee and stored at room temperature until September 20, when they were moved to the FDEP Bureau of Laboratories’ mercury clean room. The FDEP laboratory staff conducted all subsequent sample handling. Two of the three 20L bottles were filtered through a 0.45 micron filter into a new Nalgene LDPE 50L bottle. Following filtration, this 50L bottle was equipped with a motorized stirrer with a stainless steel shaft and propeller to maintain homogeneity during subsampling of the aliquots.

Individual sample bottles were provided by the participating laboratories, except for Florida International University, for whom FDEP provided cleaned bottles. The sample bottles to be filled were placed in random order and filled sequentially by thirds. The samples bottles were placed in the coolers provided by the participating laboratories and shipped to each laboratory by overnight express. Each laboratory was notified of this shipment via telephone on the day of shipment. The laboratories were asked to analyze each of six replicates for total mercury and, if it was an analyte that the laboratory normally measured, methylmercury. The FDEP laboratory was aware that each sample to be tested was from a single water sample, although other laboratories were unaware of this.

Results as reported by each laboratory are presented in Table 1. Summary statistics for each laboratory are presented in Table 2. A graphical presentation of the results using median-quartile box-plots is included in Figures 1 and 2. If you have any questions about this study, please contact Russel Frydenborg by email.

Sincerely,

/s/

Rebecca Northup, Environmental Manager
Environmental Assessment Section
Bureau of Laboratories
Division of Resource Assessment and Management

Attachments

Cc:  Tom Atkeson/FDEP
        Paul Parks/FDEP
        Bill Coppenger/FDEP

Attachment 1
Table 1. Reported Analytical Results from Florida Mercury Intercomparison Study FMIP-0999.

Table 2. Summary Statistics

All Laboratories Combined

By Laboratory

The Academy of Natural Sciences

Brooks Rand

Florida Dept of Environmental Protection

Florida International University - SERP

Frontier Geosciences

University of Michigan - Environmental & Industrial Health

USGS Middleton, Wisconsin

           Attachment 2: Laboratories Participating in the FMIP-0999 and Associated Contacts

Dr. Cynthia C. Gilmour, Assistant Curator
The Academy of Natural Sciences
Estuarine Research Center
10545 Mackall Road
St. Leonard, MD 20685

Dr. David Krabbenhoft, Research Hydrologist
Water Resources Division
US Geological Survey
8505 Research Way
Middleton, WI 53562

Dr. Jerry Keeler, Professor
Dept. of Environmental & Industrial Health
University of Michigan
109 Observatory St.
Ann Arbor, MI 48109-2029

Mr. Nicolas Bloom
Frontier Geosciences, Inc.
414 Pontius Avenue, North, Suite B
Seattle, WA 98109

Dr. Ronald D. Jones, Director
Southeast Environmental Research Program
Florida International University
University Park
Miami, FL 33199

Mr. Rick Manson
Brooks Rand, Ltd.
3950 6^th Ave. N.W.
Seattle, WA 98107

Dr. Julio Arrecis, Manager
Bureau of Laboratories
Florida Department of Environmental Protection
2600 Blair Stone Rd. MS #6510
Tallahassee, FL 32399-2400