Lab Matters Fall 2023 | Page 48

APHL 2023 POSTER ABSTRACTS

central nervous system . Measurement of VOC urinary metabolites provides easy sampling ( non-invasive ) and data complementary to other modes of sampling for VOC exposure . In our method , we measure stable VOC mercapturic acid metabolites , formed with a high degree of specificity via the glutathione pathway , making them unique biomarkers . Our analytical method under development utilizes reversed-phase , ultra-high performance liquid chromatography ( RP-UPLC ) coupled with electrospray ionization triple quadrupole mass spectrometry in negative mode ( negative ESI-MS / MS ) to simultaneously identify and quantify 31 urinary VOC metabolites of acrolein , acrylamide , acrylonitrile , benzene , 1-bromopropane , 1,3-butadiene , carbon-disulfide , ethylbenzene , ethylene oxide , isoprene , N , N-dimethylsulfide , propylene oxide , styrene , tetrachloroethylene , toluene , trichloroethylene , tetrachloroethylene , vinyl chloride and xylene in urine . Our objectives are to improve the chromatographic separation of the metabolites , in addition to enhancing their MS sensitivity through optimization of the parameters of the RP-UPLC separation , ionization source and MS analyzer . A 15 mM ammonium acetate aqueous mobile phase is commonly used to improve chromatographic separation and overcome the issues associated with false ion suppression or enhancement . For some VOC metabolites , such as those from acrylamide , ethylbenzene , N , N-dimethylsulfide , and styrene , the use of a 15 mM ammonium acetate mobile phase did not result in an optimal S / N . Lower concentrations of mobile phase additive increase S / N , albeit with a decrease in peak resolution . We tested ammonium acetate solutions of various concentrations ( 15 mM , 8 mM , 3 mM and 1 mM ) and determined that 3 mM ammonium acetate mobile phase provided symmetrical peaks , adequate peak resolution and enhanced sensitivity . The optimization of the parameters of the ion source and the analyzer , and the results will be presented and discussed .

Presenter : Jonathan Gallardo , jonathan . gallardo @ cdph . ca . gov

Method Validation of Per- and Polyfluoroalkyl Substances ( PFAS ) in Human Plasma using High Pressure Liquid Chromatography Mass Spectrometry ( LC-MS / MS )

L . Zhong , D . Mathes , C . Xu , T . Fan , S . O ’ Leary ; New Jersey Department of Health Public Health and Environmental Laboratories

The properties , utility , environmental impact , and potential adverse human health outcomes of Per- and polyfluoroalkyl substances ( PFAS ) are well documented . The quantitation of PFAS in human serum liquid chromatography tandem mass spectrometry ( LC-MS / MS ) method is also well established . This project aims to expand the scope of the already validated in-house method for testing PFAS in human serum to include human plasma . The quantitation of PFAS in human serum and plasma by the same ( LC-MS / MS ) method is reported and the presence of or absence of clotting factors does not affect the accuracy of the method . The only two differences between serum and plasma are that plasma contain clotting factor and EDTA from the collection tube . During the validation we will evaluate if these differences effect the accuracy and precision . These factors can stem from known concerns associated with this analysis include matrix enhancements , suppressions , and most importantly contamination from cartridges , solvents , and other materials . Our preliminary results show excellent agreement of 12 target PFAS analyte concentrations between serum and plasma with a coefficient of variance between to 0.0104 to 0.189 in two specimens . The precision and accuracy will be assessed by repeated measurements ( n = 8 ) at two different concentration levels spiked , targeting ~ 1 ng / mL and ~ 10 ng / mL of PFAS concentration levels respectively . The accuracy must be within ± 20 % of nominal value and the calculated RSD is 0.99 .

Presenter : Linbin Zhong , linbin . zhong @ doh . nj . gov

NH PHL New Methods : Biomonitoring and Air Quality Assessment for a Targeted Study in Berlin , NH

G . Santos , M . Chatterjee , B . Wallace , M . Josefiak , K . Bush , C . Snow ; New Hampshire Department of Health and Human Services

The New Hampshire State Biomonitoring Program ( BiomonitoringNH ) plans to launch a targeted biomonitoring study to investigate linkages between environmental exposures and the corresponding body burden in residents of Berlin , NH . This town is home to a highly vulnerable population and several sources of potential chemical exposures , including some that specifically contribute to worsened air quality . Due to the potential of air inversion events , a large biomass power plant and an increased prevalence of wood-burning home heating systems , indoor and outdoor air quality in Berlin may pose an increased risk of exposure to certain contaminants and associated health risks for residents . With emphasis on implementing new methods for both clinical and environmental air quality analysis , BiomonitoringNH aims to increase testing capabilities and collect data to promote actionable change for exposure reduction in Berlin . Accomplishing this goal requires new data collection methods at the New Hampshire Public Health Laboratories ( PHL ) including the use of newly acquired air monitors and validation of a method to identify polycyclic aromatic hydrocarbon ( PAH ) metabolites in urine , as well as outlining potential data analysis to determine associations between the two datasets . For collection of environmental data , small batches of 5 to 10 PurpleAir air quality sensors will first be co-located in the same environment to determine if all of the sensors yield similar results . This quality assurance step will help to evaluate each sensor ’ s efficacy for use in the citizen science component of the Berlin study . For clinical results , PAHs remain the primary analyte of interest to evaluate the presence of PM2.5 – an invisible , yet harmful type of particulate matter found in air pollution . Participants will provide urine samples to be analyzed using a method to quantify PAH metabolite concentrations . Validation of this method at NH PHL will involve collaboration with New Jersey PHL and Centers of Disease Control and Prevention . Lastly , participants will also be asked to complete an exposure questionnaire to aid in identifying potential routes of exposure , highlighting key contaminants unique to Berlin and evaluating the potential chemical exposure risks from their everyday actions . Based on prior BiomonitoringNH study results and reports , a data analysis plan and an outline for an exposure questionnaire will be developed for the Berlin study . The outcomes of this work will guide the execution of the Berlin study over the next year .

Presenter : Grace Santos , grace . v . santos @ affiliate . dhhs . nh . gov