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Explore the detection of pharmaceutical and personal care products in the NYC Watershed, methods used, lab analysis, QC, and common problems encountered.
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Pharmaceutical and Personal Care Products in the NYC Watershed David Lipsky, Ph.D., Q.E.P. Timothy Martin, M.P.A. Ian Hurley, Ph.D. Carla Glaser, M.E.M. Water Quality New York City Department of Environmental Protection Bureau of Water Supply
Objectives • Introduction • Sampling and Analytical Approach • Preliminary Conclusions
Introduction • PPCPs (pharmaceutical and personal care products) represent a subclass of organic compounds that have been detected in surface waters, groundwater, wastewaters and drinking water throughout world. • Term “PPCP” is used loosely and is ill-defined; can include endocrine disrupting chemicals, xenobiotics, hormonally active chemicals, pesticides and newly emerging contaminants. • Sources include wastewater, runoff from agricultural fields, biosolids, urban runoff, air, and other sources.
Introduction (con’t) • Not a new issue, but a result of advances in analytical capabilities • These advances now allow research scientists to reliably detect an increasing number of organic constituents at the ng/L (part per trillion) range • However, there are only a few contract laboratories or water utility laboratories with such demonstrated capabilities • No widely available standard methods
Introduction (con’t) • Different studies looked at different analytes with different methods • No common assessment program defining procedures to follow for collecting samples and the specific PPCPs that should be targeted
Introduction (con’t) • A recent study published in ES&T by Benotti, et.al., found PPCPs in the tap water of 19 U.S. water utilities • The 11 most frequently detected compounds, all found at low levels included: atenolol, atrazine, carbamazepine, estrone, gemfibrozil, meprobamate, naproxen, phenytoin, sulfamethoxazole, TCEP, and trimethoprim
Approach • Utilize two contract labs to perform analyses • Samples collected quarterly at source water keypoints (pre-chlorination) • High degree of field and laboratory QA/QC
Approach (con’t) • 10 samples analyzed per quarter • “Clean Hands” sampling technique • QAPP • USGS collects side by side samples for independent analysis
Approach (con’t) PPCP Monitoring Sites
CROGH CATLEFF DEL18 PPCP Monitoring Locations
Approach (con’t) Samples collected &: Taken at alternating locations for each sampling event
Laboratory Minimum Reporting Limits (MRLs) • MRLs are the lowest reportable concentration for an analyte. • Normally, an MRL will be above the amount found in a blank. • Each lab must verify accuracy and precision of their results at MRLs. • Lab regulators suggest ± 50 percent of the expected value as a reasonable goal at an MRL.
PPCP “clean hands” sampling technique “Dirty hands” assisting “clean hands” in removing sample bottle from inner/outer bag.
PPCP “clean hands” sampling technique “Clean hands” taking a field blank.
PPCP “clean hands” sampling technique CRO1T SAMPLING TAP “Dirty hands” assisting “clean hands” with placing filled sample bottle back into inner/outer bag.
Laboratory QC Test-Specific Controls: • “Blanks” – negative controls – 1 per batch of 20 samples or less • Checks for target chemical picked up during lab processing of samples • Must be “non-detected”
Laboratory QC Test-Specific Controls: • “LFB” – positive controls – 1 per batch of 20 samples or less • All target compounds, at ng/L levels • Checks for target chemical lost during processing • Must be 70 – 130 percent of expected levels
Laboratory QC Sample-Specific Controls: • “Spikes” - known amounts of target compounds added to sample • Checks for masking of target compounds by interferences in samples • Check amount recovered after background is subtracted • 70 - 130 percent of expected levels
Laboratory QC Sample-Specific Controls: • “Duplicates” – 2 samples or 2 “spikes” • Compare amounts of target compounds found in matched pairs • Checks for reproducibility • Less than 30 percent difference
Laboratory QC Added to all samples and QC: • “Internal standard” • Compound NOT found in samples • Added just before analysis • Controls for short-term changes in instrument performance
Laboratory QC Added to all samples and QC: • “Surrogate” • Compound NOT found in samples and chemically similar to target compounds • Added before sample QC processing • Controls for losses of target compounds during processing
QC Problems Decreasing as labs get more experience, modify methods
QC Problems Common QC problems: • Low recoveries of “surrogate” from samples (testosterone-d3, ibuprofen-d3, acetaminophen-d4) • Low recoveries of target compounds from spikes (sulfamethoxazole, chlorotetracycline) • Possible cause: background interference (with internal standards?)
QC Problems Less common QC problems: • Low recoveries of target compounds from “LFB” (fluoxetine, bacitracin) • Possibly cause: loss during extraction from reagent water
Conclusion • Program appears to be providing credible results • Good agreement among duplicates • Few detects in blanks • Clean hands technique more time consuming but advisable to reduce cross-contamination as a possible source of error • Good agreement between laboratories
Conclusion (con’t) • Need detailed expert review of contract lab results • Continues to require high degree of interaction between DEP and contract lab personnel to address QA/QC issues • Need additional scientific/QA review before publishing results
Questions? Thank You