Lab Matters Fall 2024 | Page 42

APHL 2024 POSTER ABSTRACTS

supernatant is loaded on the SPE plate ( Oasis ® WAX ) and washed with 200 μL 1 % formic acid and 1:3 acetonitrile : water solution . A conditioning step is then performed with 200 μL 2 % ammonia in methanol , 200 μL methanol and 200 μL 1 % formic acid . Then eluted with 50 μL methanol and 100 μL 2 % ammonia in methanol . The samples are dried at 70 º and reconstituted with 120 μL mobile phase 72:28 A : B solution . Then injected into Sciex 7500 LC-MS instrument with UHPLC Guard 3PK column / InfinityLab PFC Delay column for LC-MS analysis . A new SPE method was successfully created using Janus ® instrument . This new SPE method reduces the time it takes to prepare 48 samples from 8 to 2 hours . Initial chromatographic peaks shapes were poor but were resolved by dissolving the sample in initial mobile phase conditions . Low analyte peak intensities were first observed because of dilutions but increasing the injection volume from 40 μl to 100 μl fixed this problem . The new method produces acceptable calibration curves ; the R2 are between 0.991 to 0.996 for all analytes . The accuracy of matrix spiked samples is within ± 30 % of the nominal value .

Presenter : Zhan Quan Li , ben . li0106 @ gmail . com

Forever Chemicals in Drinking Water : Two Fellows ’ Perspective on Testing for Per- and Polyfluoroalkyl Substances in a Public Health Lab

N . Brinza , S . Fleegal , B . Knouse , M . Wills , S . Muneem , S . Urban , Maryland Department of Health - Laboratories Administration

Per- and polyfluoroalkyl substances ( PFAS ) are a chemical class that can survive for years in the environment and > 95 % of US residents carry detectable levels in their blood . Scientific understanding of the health impact the thousands of PFAS have on human health is still emerging , but the current most studied PFAS — perfluorooctane sulfonate ( PFOS ) and perfluorooctanoic acid ( PFOA )— have human studies demonstrating negative impacts on reproductive health , kidney health , thyroid health and immune response .

A major pathway of PFAS entering the blood comes from consuming PFAS contaminated water and food . This poster presents an overview of the PFAS testing process in drinking water using liquid chromatography-mass spectrometry ( LC-MS ), from receiving samples to submitting the final results through StarLIMS . Extra emphasis is placed on how EPA methods are adapted to the capabilities of the Maryland Department of Health Laboratories Administration , such as using automated solid phase extraction and various types of MS detection methods , including triple-quadrupole MS and time-of-flight MS .

Presenter : Nicholas Brinza , nbrinza004 @ gmail . com

Highly Pathogenic Avian Influenza Testing of Domestic Animals in the State of Montana

E . Young , E . Schwarz , Montana Veterinary Diagnostic Laboratory

Highly pathogenic avian influenza ( HPAI ) is an infectious viral disease spread by wild migratory waterfowl that causes severe illness and death in poultry . Since the onset of the outbreak in early 2022 , addressing surveillance and response to HPAI has become a critical priority area for the National Animal Health Laboratory Network ( NAHLN ). During the present outbreak , there have been reports of HPAI-infected wild mammals in Montana and across the United States . Birds of prey , mesocarnivores ( such as foxes , skunks and coyotes ) and wild felids ( bobcats , mountain lions , etc .) likely become exposed to the virus after ingestion of an HPAI-infected bird . Although there seems to be a low risk of natural transmission to domestic mammals , the currently circulating strain of HPAI ( H5N1 , clade 2.3.4.4b ) has been reported to infect domestic dogs , domestic cats and a variety of mammals in zoologic collections , causing significant morbidity and mortality . In 2023 , a domestic cat died in France and at least one dog died in Canada due to HPAI infection . Similarly , six cats also have died in Nebraska , Oregon and Wyoming after contracting the virus . As of yet , the state of Montana has not had the opportunity to pursue HPAI testing in domestic mammals . To ascertain whether there is evidence of HPAI infection in domestic mammals in Montana ( dogs , cats , horses , cows , sheep , goats , etc .), this study will utilize real time polymerase chain reaction ( RT-PCR ) to determine if influenza A virus nucleic acids are present in brain tissue samples of domestic mammals that were previously submitted to the Montana Veterinary Diagnostic Laboratory for rabies testing . There is growing concern among human public health officials over the possibility of HPAI becoming established in human populations and given the proximity in which humans live to domestic mammals , understanding how the virus is changing to more efficiently infect different species is crucial for surveillance purposes , monitoring the spread of HPAI and understanding the future potential for spillover to humans .

Presenter : Enrico Young , enrico . dicastroyoung @ mt . gov

Immunoaffinity Magnetic Beads for Microcystins Capture and Concentration in Biological Samples

L . Ruth 1 , S . Oehrle 2 , B . Polyak 1 , F . Rubio 1 , Gold Standard Diagnostics Horsham 1 , Waters Corporation 2

Cyanotoxins are a category of toxins produced by cyanobacteria ( also known as blue-green algae ). They are particularly prevalent in certain bodies of water , where under favorable environmental conditions they can reproduce exponentially to form harmful algal blooms ( HABs ), which pose a significant health risk . Microcystins , a group of toxins with hepatotoxic effects , are the most commonly found cyanotoxins . The US EPA has issued health advisories for these toxins in drinking and recreational water , but various government agencies , public health laboratories and academic researchers also have an interest in the detection of microcystins in biological samples , primarily urine and blood serum to assess exposure .

Due to the complex nature of urine and blood serum , as well as possibly low levels of microcystins in these samples , sample cleanup and concentration is needed to prepare biological samples for downstream detection with sensitive analytical techniques such as LC-MS , enzymatic assays and ELISA . Immunoaffinity magnetic beads ( IMB ) have emerged as an effective cleanup method . IMB , synthesized by conjugating antibodies onto magnetic nanoparticles , are mixed with a biological sample whereby the antibody binds to the target of interest . The IMB-target complex is then separated from the matrix using a strong magnet . Due to antigen-antibody specificity , the IMB cleanup method possesses high affinity for the target of interest and by varying the elution volume , can result in a 10-fold concentration of the target , bringing it to detectable levels .

Gold Standard Diagnostics Horsham ( GSDH ) has developed a novel microcystins in urine and blood serum IMB cleanup kit for sample pre-treatment and concentration prior to downstream analysis . The