Lab Matters Summer 2018 | Page 48

APHL 2018 Annual Meeting Poster Abstracts

Environmental Health activities, including annual environmental laboratory conferences, laboratory standardization and method development workgroups, various trainings and communications to connect environmental laboratories. The second cooperative agreement was awarded in 2011 and concluded November 30, 2017. During this time, APHL continued to play a leadership role by serving as an environmental laboratory sector liaison, organizing conferences, task forces and work group meetings, disseminating and sharing information and providing technical assistance through training opportunities. This poster will explore the quantitative and qualitative measures of this nearly twelve year partnership between US EPA and APHL, as well as its ultimate effect on strengthening environmental laboratories.

Presenter: Sarah Wright, MS, Association of Public Health Laboratories, Silver Spring, MD, Phone: 240.485.2730, Email: sarah. wright @ aphl. org

Gas Chromatography / Tandem Mass Spectrometry Analysis of Volatile Organic Compounds

K. Castor, T. Kim and M. Koltunov, California Department of Toxic Substances Control, Pasadena, CA

Our public health is greatly affected by our environment. Depending on where we live and work, we could be exposed to a variety of environmental contaminants; from the air we breathe, to the water we drink, to the soil on which we build our houses. At The Environmental Chemistry Laboratory in Pasadena, our mission statement includes striving to be leaders in analytical and environmental chemistry to protect California’ s people and environment from toxic harm. One class of compounds that we are interested in from a public health aspect is volatile organic compounds( VOCs). VOCs are a group of compounds with low boiling points( below 200 ° C), low to medium water solubility and low molecular weights. They are anthropogenic( man-made) contaminants found in different matrices such as soil, waste water and indoor air. Due to their prevalence and toxic nature, the Public Health Goal( PGH) in drinking water for various VOCs are in the very low µ g / L and pg / L range, which emphasizes the need to enable detection of these compounds at very low levels. We have developed a GC / triple quadrupole mass spectrometric( GC / MS-QQQ) analysis for VOC quantitation using a dynamic multiple reaction monitoring method( dMRM). Samples are introduced using a purge and trap system. Our dMRM method allows for detection down to 0.5 µ g / L with great selectivity and high sensitivity for desired compounds. Additionally, we can analyze 62 compounds in a single run, allowing for reduced analysis time.

Presenter: Katherine Castor, PhD, California Department of Toxic Substances Control, Pasadena, CA, Phone: 626.304.2692, Email: katherine. castor @ dtsc. ca. gov

Gas Chromatography / Tandem Mass Spectrometry Analysis of Pesticides

K. Castor, J. Men and M. Koltunov, California Department of Toxic Substances Control, Pasadena, CA

Our public health is greatly affected by our environment. Depending on where we live and work, we could be exposed to a variety of environmental contaminants; from the air we breathe, to the water we drink, to the soil on which we build our houses. At The Environmental Chemistry Laboratory in Pasadena, our mission statement includes striving to be leaders in analytical and environmental chemistry to protect California’ s people and environment from toxic harm. One class of compounds that we are interested in from a public health aspect is pesticides. Organophosphorus and organochlorine pesticides are neurotoxic and are the active ingredients in many insecticides used in agricultural, residential and commercial landscape settings. After their use, pesticides can remain in the soil. Parathion, an organophosphorus compound, has a low oral LD50 of 3 – 8 mg / kg, which emphasizes the need to enable detection of these compounds at very low mg / kg or µ g / kg levels. Traditional analysis relies on separation and detection of pesticides using gas chromatography coupled to a flame photometric detector( GC / FPD) or electron capture detector( GC / ECD). These techniques detect the signals from either the phosphorus or chlorine atoms and rely on a second column confirmation, resulting in a longer analysis time and a higher detection limit(> 50 µ g / kg). We have developed a GC / triple quadrupole mass spectrometric( GC / MS-QQQ) analysis for multiple compounds of interest that uses a dynamic multiple reaction monitoring( dMRM) method to enable specific mass detection of each compound, thus eliminating the second column confirmation. In addition, the dMRM method allows for detection down to 1- 2.5 µ g / kg by minimizing interference from other compounds. The quantitation is based on specific mass and fragmentation pattern of each analyte of interest and is a very powerful method to analyze soil contaminants.

Presenter: Katherine Castor, PhD, California Department of Toxic Substances Control, Pasadena, CA, Phone: 626.304.2692, Email: katherine. castor @ dtsc. ca. gov

Evaluating Associations Between PFAS Detected in Drinking Water and Human Serum in Northern California

S. Crispo Smith, M. Petreas and J. S. Park, California Department of Toxic Substances Control, Pasadena, CA

Per- and polyfluoroalkyl substances( PFASs) are a large class of anthropogenic and persistent chemicals, some of which bioaccumulate and are associated with testicular and kidney cancer, high cholesterol, ulcerative colitis, thyroid disease and preeclampsia. Public concern regarding the ubiquity and potential toxicity of legacy and next-generation PFASs in drinking water has led to increased regulatory pressure requiring more sensitive and selective analytical methods. Our previous study suggests drinking water could be a significant exposure route for PFASs in the general population( 1). To evaluate any association between drinking water and serum PFAS concentrations, here we apply newly developed analytical methods to quantify PFAS in human serum and tap water collected from San Francisco Bay and Sacramento locations in Northern California. Using 0.25 mL of serum and 250 mL of water sample, the analyses were performed by using liquid chromatography( Nexera UFLC system, Shimadzu) coupled to a triple-quadrupole tandem mass spectrometer( SCIEX QTRAP 5500 MS / MS system). In both matrices, we were able to confidently measure 29 PFASs, including 10 out of the 12 analytes listed in EPA method 537: eight perfluoroalkyl carboxylic acids( PFCAs), six telomer acids( TAs), four perfluoroalkyl sulfonates( PFASs), four polyfluorinated phosphate esters( PAPs), three perfluororoctanesulfonamides( FOSAs), two telomer sulfonates( TSs), one perfluoroalkylphosphinate( PFPi) and one perfluoroalkyl phosphonic acid( PFAPA). Our drinking water method has detection limits sufficiently sensitive to comply with