W10 PM Environmental Interactions of Marine Antifoulants
Wednesday, 16 November 2005: 1:50 PM - 5:30 PM in 341-342

(SAP-1117-821797) Monitoring of antifouling pesticides in the coastal waters of South Carolina, USA.

Sapozhnikova, Y.¹, Wirth, E.¹, Clum, F.¹, Fulton, M.¹, ¹ NOAA/National Ocean Service, Charleston, SC, USA

ABSTRACT- After the banning of tributyltin (TBT), new biocides and previously known pesticides were brought to market as substitutes for organotins. Irgarol 1051 and Sea-Nine 211 are currently the most widely used organic booster biocides. Chlorothalonil, dichlofluanid, diuron, and TCMTB are also widely used antifouling pesticides in many countries. Since these alternatives to TBT are also toxic, their contamination in the aquatic environment has been a topic of increasing importance in recent years. The purpose of this study was to measure the concentrations of Irgarol 1051, its major metabolite GS26575 (also known as M1), Sea-Nine 211, and other antifouling pesticides: diuron, chlorothalonil, dichlofluanid and TCMTB in the coastal waters of South Carolina. Water samples were collected from nine locations on the Wando River in close proximity to the Charleston Harbor, South Carolina in spring of 2005. The samples were extracted and analyzed for antifouling pesticides using Solid-Phase Extraction (SPE) (C18 SPE cartridge) and Liquid Chromatography Tandem Mass Spectrometry (LC-MS-MS) respectively. The chromatographic separation was achieved using a C18 HPLC reverse phase column. Irgarol 1051, GS26575, Sea-Nine 211 and diuron were analyzed in positive ionization mode, while dichlofluanid, chlorothalonil and TCMTB - in negative mode. Chlorotoluron dimethyl-d6 was used as an internal standard. Calibration curves were linear within 1.0-1,000.0 ng/ml with r² being greater than 0.98. Irgarol 1051 concentrations ranged from 3.7 to 18.4 ng/L, and GS26575 concentrations - from 1.2 to 7.6 ng/L. Diuron concentrations reached up to 197.4 ng/L. These three compounds were detected in all samples, indicating high dispersal and potential contamination in this area. Other antifouling pesticides were not detected at this time. We plan to continue monthly monitoring of antifouling compounds in South Carolina's coastal waters to determine a seasonal trend.

Key words: antifouling pesticides, coastal waters