The Department of Pesticide Regulation Environmental Monitoring Branch has successfully used ELISA for analyses of pesticides in soil and water samples for over a decade using both in-house assays (Goh 1992a, 1992b, 1993, 1996) and commercially available kits (Goh 1990, 1991). We recently evaluated a commercial diazinon kit for its sensitivity, selectivity, accuracy and precision, etc. for surf...

Water samples were concentrated by the modified adsorption-elution technique followed by speedVac reconcentration of the filter eluates. Reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) was used to detect rotavirus RNA in concentrates of the water. The detection limit of the rotavirus determined by RT-nested PCR alone was about 1.67 plaque forming units (PFU) per RT-PCR as...

Perchlorate has been added to the U.S. Environmental Protection Agency's Drinking Water Contaminant Candidate List (CCL). The present work describes the analysis of perchlorate in water by liquid-liquid extraction followed by flow injection electrospray mass spectrometry (ESI/MS). Cationic surfactants, mostly alkyltrimethyl-ammonium salts, are used to ion-pair aqueous perchlorate, forming extra...

The total bacterial community of an experimental slow sand filter (SSF) was analyzed by denaturing gradient gel electrophoresis (DGGE) of partial 16S rRNA gene PCR products. One dominant band had sequence homology to Legionella species, indicating that these bacteria were a large component of the SSF bacterial community. Populations within experimental and commercial SSF units were studied by u...

   In this study, a method for extraction and preconcentration of trace amounts of organophosphorus pesticides (OPPs) in environmental water using magnetic solid phase extraction (magnetic-SPE) followed by high performance liquid chromatography (HPLC) with UV detection was developed. The magnetic carbon nanotube adsorbents (Fe3O4/CNT) were synthesized by grafting carbo...

This paper aims to gather and discuss important information about nonylphenol, such as physical chemistry properties, toxicity and analytical methods in various matrices. As a degradation product of ethoxylated alkylphenols, nonylphenol presents a higher degree of reactivity than its precursor. Due to its harmful effects on the environment, use and production of nonylphenol has been banned in E...