Lab Matters Fall 2023 | Page 42

APHL 2023 POSTER ABSTRACTS

Evaluating an Automated Solid Phase Extraction System to Extract Per- and Polyfluoroalkyl Substances from Delaware River Water , Following US Environmental Protection Agency Method 1633

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

The New Jersey Department of Health aims to implement EPA Method 1633 to extract 40 per- and polyfluoroalkyl substances ( PFAS ) from river water by solid phase extraction ( SPE ) and quantify them by liquid chromatography-tandem mass spectrometry . The SPE method utilizes weak anion exchange ( WAX ) SPE cartridges conditioned with methanolic ammonium hydroxide and formic acid , followed by loading 500 mL of sample , rinsing with water and buffer , and eluting with methanolic ammonium hydroxide . A vacuum facilitates flow through the cartridge on the manual SPE . Our lab has successfully extracted 39 of the 40 analytes within 70- 130 % accuracy using this method . However , it requires continuous monitoring and adjustments , making it time consuming and labor intensive . Our goal is to reduce this burden by automating the SPE method using the Promochrom SPE-03 liquid handler . The automated SPE uses the same protocol , however , it draws the liquids into the cartridge using syringes , and the samples flow through the cartridge by gravity . As a result , it has introduced complications such as cartridge clogging , leaks , and poor elution due to solid particulates and algae in the river water samples . These lead to inadequate analyte recovery , incomplete extraction , and inconsistency between samples . We have improved the automated protocol by changing various conditions such as SPE cartridges , solvents , sample pre-treatment , and sample volume . The Agilent Bond Elute WAX cartridges were more successful in completing the extraction compared to two other WAX cartridges due to larger particle sizes . Two alternative WAX SPE protocols , EPA method 533 and a method published by Coggan et al . at Agilent Technologies , were also tested . While these methods experienced less clogging , they suffered the loss of additional analytes . Lastly , the samples were centrifuged to separate the solids from the bulk of the liquid to allow a majority of the sample to pass through without clogging , before adding the solids at the end . This prevented the samples from clogging during loading , but they subsequently clogged during rinsing and elution , preventing the SPE run from completing . Reducing the sample volume to 250 mL significantly reduced the clogging issue for most samples but sacrificed the sensitivity . Thus far , the optimized method achieves recoveries between 60- 150 % for all analytes . However , the clogging is still not completely evitable . In conclusion , automated SPE has yet to be an effective approach for EPA method 1633 for river water in our lab , primarily because it relies solely on gravity for loading and eluting . Further experimentation will involve incorporating vacuum power , which may overcome the sample clogging issue and achieve method requirements .

Presenter : Devon Baird , devon . baird @ doh . nj . gov

Evaluating Chemical Exposures from “ Non-toxic ” Nail Polishes

P . Callaway , K . Anderson ; National Institute for Occupational Safety and Health , US Centers for Disease Control and Prevention

In response to consumer concerns over nail product toxicity , the nail industry introduced n-free polishes — polishes that claim to be free of n-number of chemicals . The original n-free ( 3-free ) polishes claimed not to contain formaldehyde , toluene or dibutyl phthalate ( DBP ), chemicals that have been associated with respiratory health problems , cancer , and poor reproductive health outcomes . Now , there are a wide variety of n-free polishes with many claiming to be 10 or more free . Despite the proliferation of these products , there is evidence to suggest that some n-free polishes contain chemicals they claim to be free of . Some of these chemicals can cause adverse reproductive outcomes and pose a risk to the high proportion of nail salon workers who are women of childbearing age . While the development of n-free polish was largely consumer driven , nail salon workers have higher exposures and thus are likely at greater risk for negative health outcomes from these nail products . Understanding what chemicals nail salon workers are exposed to , and at what levels , can help establish risks associated with nail product use and can enable workers to make informed decisions about product use . In this study , we measured chemical exposures generated while painting nails with 10 brands of n-free polishes using real-time and time-integrated air sampling . Real-time measurements were conducted using a photoionization detector ( PID , Tiger , Ion Science ) to measure total volatile organic compounds ( TVOCs ) and a FTIR ( Fourier-transform infrared spectroscopy ) gas analyzer ( DX4040 , Gasmet ) to measure individual compounds . Time-integrated samplers were used to measure formaldehyde ( OSHA Method 1007 , UMEx passive badges , SKC ), DBP ( OSHA Method 104 , OVS tubes , SKC ) and triphenyl phosphate ( TPhP , NIOSH Method 5038 , mixed cellulose ester filters , SKC ), a common substitute for DBP thought to have similar health effects . Airborne concentrations were measured while two coats of polish were applied to artificial nails on a mannikin in an exposure chamber and for two hours after application . Results from approximately 40 trials indicated little variation (+/ - < 1 ppm ) in mean TVOC concentration between polishes and no correlation ( rho = 0.18 , p = 0.22 , Spearman ’ s ) with number of n-free claims . Mean TVOC concentrations ranged from 0.22 to 0.86 ppm with peak concentrations ranging from 2.69 to 44.26 ppm , depending on polish brand . Despite all polishes in this study claiming to be 3-free , preliminary results suggest over 80 % had measurable formaldehyde concentrations and over 70 % of polishes had measurable toluene concentrations . However , neither DBP nor TPhP were detected . This study highlights that despite industry claims , n-free polishes may still contain chemicals associated with negative health effects and that more studies are necessary to understand the true chemical exposures of nail salon workers .

Presenter : Perri Callaway , tqa8 @ cdc . gov

Implementing Automated Extraction for High Throughput Environmental Testing

M . Wills , Z . Cao , A . Frost , X . Hu , S . Urban ; Maryland Department of Health Laboratories Administration

Per- and polyfluoroalkyl substances ( PFAS ) have become so pervasive in our water that the Biden Administration recently pledged $ 5 billion to states addressing the contamination . With this call to action comes the need for robust technology to keep pace with the increasing scale of sample testing . We compared manual extraction to an 8-channel automated solid-phase extractor ( SPE- 03 ) over three EPA PFAS methods ( 537.1 , 533 , and 1633 ). Our