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Update in the Development of a Drinking Water Method for the Measurement of Select Organic Contaminants in Drinking Water Using Hydrophilic-Modified Polymeric SPE and GC/MS
Oral Presentation
Prepared by P. Grimmett
USEPA ORD, 26 W. Martin Luther King , Cincinnati, Ohio, 45268
Contact Information: grimmett.paul@epa.gov; 513-569-7663
ABSTRACT
In October 2009, the USEPA’s Office of Ground Water and Drinking Water (OGWDW) published its latest Drinking Water Contaminant Candidate List (CCL 3). This list contains potential drinking water contaminants that the agency will consider for regulation. One of the key pieces of information necessary to make a regulatory determination for a contaminant is its nationwide occurrence. Historically, OGWDW has collected the necessary occurrence data under its Unregulated Contaminant Monitoring Regulations (UCMRs). In order for a contaminant to be included in a UCMR, a standardized analytical method for its measurement in drinking water must be available. A group of compounds from CCL 3, which were not amenable to any current EPA method, were evaluated for grouping into a new method. The group consists of two industrial compounds (o-toluidine and quinoline), a pesticide (dimethipin), a fungicide (captan), and a food additive (butylated hydroxyanisole, BHA). The current procedure requires preservation of a 1-L drinking water sample with L-ascorbic acid, EDTA, Trizma buffer, and diazolidinyl urea, followed by solid phase extraction (SPE) with a hydrophilic-modified polymeric (divinylbenzene, 500 mg) sorbent. Sample analyses were then performed using gas chromatography/mass spectrometry (GC/MS). Extraction efficiencies of all compounds in fortified laboratory reagent water (LRW) ranged from 92-123% in low level spikes (0.1 µg/L), 94-112% in mid-level spikes (1 µg/L), and 85-99% in high level spikes (5 µg/L). Extraction efficiencies of all compounds in fortified groundwater source drinking water (hardness > 350 mg/L) ranged from 117-133% in low level spikes (0.1 µg/L), 86-113% in mid-level spikes (1 µg/L), and 86-101% in high level spikes (5 µg/L). Extraction efficiencies of all compounds in fortified surface water source drinking water ranged from 86-108% in mid-level spikes (1 µg/L) and 76-109% in high level spikes (5 µg/L). Future work will include challenging the extraction and analysis process with laboratory created waters high in total organic carbon (TOC ~ 2 mg/L) and challenging the preservation scheme with a 28 day holding time study. Ideally, this method will contain the option for selected ion monitoring (SIM), to achieve a Lowest Concentration Minimum Reporting Level (LCMRL) below the health reference level (HRL) for quinoline (0.01 µg/L).
(Related Session: Topics in Drinking Water)
Oral Presentation
Prepared by P. Grimmett
USEPA ORD, 26 W. Martin Luther King , Cincinnati, Ohio, 45268
Contact Information: grimmett.paul@epa.gov; 513-569-7663
ABSTRACT
In October 2009, the USEPA’s Office of Ground Water and Drinking Water (OGWDW) published its latest Drinking Water Contaminant Candidate List (CCL 3). This list contains potential drinking water contaminants that the agency will consider for regulation. One of the key pieces of information necessary to make a regulatory determination for a contaminant is its nationwide occurrence. Historically, OGWDW has collected the necessary occurrence data under its Unregulated Contaminant Monitoring Regulations (UCMRs). In order for a contaminant to be included in a UCMR, a standardized analytical method for its measurement in drinking water must be available. A group of compounds from CCL 3, which were not amenable to any current EPA method, were evaluated for grouping into a new method. The group consists of two industrial compounds (o-toluidine and quinoline), a pesticide (dimethipin), a fungicide (captan), and a food additive (butylated hydroxyanisole, BHA). The current procedure requires preservation of a 1-L drinking water sample with L-ascorbic acid, EDTA, Trizma buffer, and diazolidinyl urea, followed by solid phase extraction (SPE) with a hydrophilic-modified polymeric (divinylbenzene, 500 mg) sorbent. Sample analyses were then performed using gas chromatography/mass spectrometry (GC/MS). Extraction efficiencies of all compounds in fortified laboratory reagent water (LRW) ranged from 92-123% in low level spikes (0.1 µg/L), 94-112% in mid-level spikes (1 µg/L), and 85-99% in high level spikes (5 µg/L). Extraction efficiencies of all compounds in fortified groundwater source drinking water (hardness > 350 mg/L) ranged from 117-133% in low level spikes (0.1 µg/L), 86-113% in mid-level spikes (1 µg/L), and 86-101% in high level spikes (5 µg/L). Extraction efficiencies of all compounds in fortified surface water source drinking water ranged from 86-108% in mid-level spikes (1 µg/L) and 76-109% in high level spikes (5 µg/L). Future work will include challenging the extraction and analysis process with laboratory created waters high in total organic carbon (TOC ~ 2 mg/L) and challenging the preservation scheme with a 28 day holding time study. Ideally, this method will contain the option for selected ion monitoring (SIM), to achieve a Lowest Concentration Minimum Reporting Level (LCMRL) below the health reference level (HRL) for quinoline (0.01 µg/L).
(Related Session: Topics in Drinking Water)