Microbial Inhibitors for U.S. EPA Drinking Water Methods for the Determination of Organic Compounds

• Published in: Environmental science & technology Vol. 35; no. 20; pp. 4103 - 4110
• Main Authors: Winslow, Stephen D, Pepich, Barry V, Bassett, Margarita V, Wendelken, Steven C, Munch, David J, Sinclair, James L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.10.2001
• Subjects: Anti-Infective Agents, Local - chemistry; Antidotes - chemistry; Applied sciences; Copper Sulfate - chemistry; Drinking water; Drinking water and swimming-pool water. Desalination; Environmental Monitoring; Exact sciences and technology; Microorganisms; Organic Chemicals - analysis; Organic chemistry; Pollution; Regulatory agencies; Specimen Handling; United States; United States Environmental Protection Agency; Urea - analogs & derivatives; Urea - chemistry; USA; Water Microbiology; Water Pollutants, Chemical - analysis; Water Supply; Water treatment; Water treatment and pollution; Drinking water; Chemical analysis; Water quality; Check; Sample conservation; Disinfection; Metabolic inhibitor; Performance; Antimicrobial agent
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es010661b

Preservation of chemical analytes in drinking water samples is necessary to obtain accurate information concerning contaminant occurrence. Sample preservation to prevent biodegradation is important for most samples and analytes. With the unique demands of environmental methods, it is not always possible to kill all microorganisms without having undesirable effects. To find a suitable preservative, the sample, analysis, and preservation needs should be considered. During method development of U.S. Environmental Protection Agency (EPA) Methods 526 (for unstable semivolatile compounds) and 532 (for phenylurea pesticides), a number of studies were conducted to identify compatible microbial inhibitors. Copper sulfate was successfully used in Method 532 and is an excellent first-choice antimicrobial agent for many applications. Copper sulfate can catalyze hydrolysis reactions for some pesticides such as those analyzed in Method 526. Under these conditions, a nonmetal compound of antimicrobial activity must be considered. During the development of Method 526, a survey of alternate organic based antimicrobial compounds found that diazolidinyl urea worked well in the method. Several other candidate microbial inhibitors were identified that could have application to other environmental methods. A general approach to selecting antimicrobial compounds in future environmental methods in water matrixes is discussed.