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Rebekah E Wharton
Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy, Atlanta, GA 30341, USA

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Journal article
Published: 04 January 2021 in Journal of Analytical Toxicology
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Health-care workers, laboratorians and overdose prevention centers rely on commercial immunoassays to detect the presence of fentanyl; however, the cross-reactivity of fentanyl analogs with these kits is largely unknown. To address this, we conducted a pilot study evaluating the detection of 30 fentanyl analogs and metabolites by 19 commercially available kits (9 lateral flow assays, 7 heterogeneous immunoassays and 3 homogenous immunoassays). The analogs selected for analysis were compiled from the Drug Enforcement Administration and National Forensic Laboratory Information System reports from 2015 to 2018. In general, the immunoassays tested were able to detect their intended fentanyl analog and some closely related analogs, but more structurally diverse analogs, including 4-methoxy-butyryl fentanyl and 3-methylfentanyl, were not well detected. Carfentanil was only detected by kits specifically designed for its recognition. In general, analogs with group additions to the piperidine, or bulky rings or long alkyl chain modifications in the N-aryl or alkyl amide regions, were poorly detected compared to other types of modifications. This preliminary information is useful for screening diagnostic, forensic and unknown powder samples for the presence of fentanyl analogs and guiding future testing improvements.

ACS Style

Rebekah E Wharton; Jerry Casbohm; Ryan Hoffmaster; Bobby N Brewer; M G Finn; Rudolph C Johnson. Detection of 30 Fentanyl Analogs by Commercial Immunoassay Kits. Journal of Analytical Toxicology 2021, 45, 111 -116.

AMA Style

Rebekah E Wharton, Jerry Casbohm, Ryan Hoffmaster, Bobby N Brewer, M G Finn, Rudolph C Johnson. Detection of 30 Fentanyl Analogs by Commercial Immunoassay Kits. Journal of Analytical Toxicology. 2021; 45 (2):111-116.

Chicago/Turabian Style

Rebekah E Wharton; Jerry Casbohm; Ryan Hoffmaster; Bobby N Brewer; M G Finn; Rudolph C Johnson. 2021. "Detection of 30 Fentanyl Analogs by Commercial Immunoassay Kits." Journal of Analytical Toxicology 45, no. 2: 111-116.

Journal article
Published: 13 December 2019 in Toxins
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Microcystins (MC) and nodularin (NOD) are toxins released by cyanobacteria during harmful algal blooms. They are potent inhibitors of protein phosphatases 1 and 2A (PP1 and PP2A) and cause a variety of adverse symptoms in humans and animals if ingested. More than 250 chemically diverse congeners of MCs have been identified, but certified reference materials are only available for a few. A diagnostic test that does not require each reference material for detection is necessary to identify human exposures. To address this need, our lab has developed a method that uses an antibody to specifically isolate MCs and NOD from urine prior to detection via a commercially available PP2A kit. This assay quantitates the summed inhibitory activity of nearly all MCs and NOD on PP2A relative to a common MC congener, microcystin-LR (MC-LR). The quantitation range for MC-LR using this method is from 0.050–0.500 ng/mL. No background responses were detected in a convenience set of 50 individual urines. Interday and intraday % accuracies ranged from 94%–118% and relative standard deviations were 15% or less, meeting FDA guidelines for receptor binding assays. The assay detected low levels of MCs in urines from three individuals living in close proximity to harmful algal blooms (HABs) in Florida.

ACS Style

Rebekah E. Wharton; Brady R. Cunningham; Adam M. Schaefer; Sophia M. Guldberg; Elizabeth I. Hamelin; Rudolph C. Johnson. Measurement of Microcystin and Nodularin Activity in Human Urine by Immunocapture-Protein Phosphatase 2A Assay. Toxins 2019, 11, 729 .

AMA Style

Rebekah E. Wharton, Brady R. Cunningham, Adam M. Schaefer, Sophia M. Guldberg, Elizabeth I. Hamelin, Rudolph C. Johnson. Measurement of Microcystin and Nodularin Activity in Human Urine by Immunocapture-Protein Phosphatase 2A Assay. Toxins. 2019; 11 (12):729.

Chicago/Turabian Style

Rebekah E. Wharton; Brady R. Cunningham; Adam M. Schaefer; Sophia M. Guldberg; Elizabeth I. Hamelin; Rudolph C. Johnson. 2019. "Measurement of Microcystin and Nodularin Activity in Human Urine by Immunocapture-Protein Phosphatase 2A Assay." Toxins 11, no. 12: 729.

Research article
Published: 22 August 2018 in Chemical Research in Toxicology
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Microcystins are toxins produced by many cyanobacteria species, which are often released into waterways during blue-green algal blooms in freshwater and marine habitats. Consumption of microcystin-contaminated water is a public health concern as these toxins are recognized tumor promoters and are hepatotoxic to humans and animals. A method to confirm human exposures to microcystins is needed; therefore, our laboratory has developed an immunocapture liquid chromatography tandem mass spectrometry (LC-MS/MS) method targeting the conserved adda portion of microcystins for quantitation of a prevalent and highly toxic congener of microcystin, microcystin-LR (MC-LR). An acute exposure method was initially evaluated for accuracy and precision by analyzing calibrators and quality control (QC) samples ranging from 0.500 – 75.0 ng/mL in urine. All calibrators and QC samples characterized were within 15% of theoretical concentrations. Analysis of acutely exposed mouse urine samples using this method identified MC-LR levels from 10.7 to 33.9 ng/mL. Since human exposures are anticipated to result from low-dose or chronic exposures, a high sensitivity method was validated with twenty calibration curves and QC samples ranging from 0.0100 – 7.50 ng/mL. Relative standard deviations (RSDs) and inaccuracies of these samples were within 15%, meeting FDA guidelines for analytical methods, and the limit of detection was 0.00455 ng/mL. In conclusion, we have developed a method which can be used to address public health concerns by precisely and accurately measuring MC-LR in urine samples.

ACS Style

Rebekah E. Wharton; Geovannie Ojeda-Torres; Brady Cunningham; Melanie C. Feyereisen; Kasey L. Hill; Nicole L. Abbott; Craig Seymour; Donna Hill; Johnsie Lang; Elizabeth I. Hamelin; Rudolph C. Johnson. Quantification of Microcystin-LR in Human Urine by Immunocapture Liquid Chromatography Tandem Mass Spectrometry. Chemical Research in Toxicology 2018, 31, 898 -903.

AMA Style

Rebekah E. Wharton, Geovannie Ojeda-Torres, Brady Cunningham, Melanie C. Feyereisen, Kasey L. Hill, Nicole L. Abbott, Craig Seymour, Donna Hill, Johnsie Lang, Elizabeth I. Hamelin, Rudolph C. Johnson. Quantification of Microcystin-LR in Human Urine by Immunocapture Liquid Chromatography Tandem Mass Spectrometry. Chemical Research in Toxicology. 2018; 31 (9):898-903.

Chicago/Turabian Style

Rebekah E. Wharton; Geovannie Ojeda-Torres; Brady Cunningham; Melanie C. Feyereisen; Kasey L. Hill; Nicole L. Abbott; Craig Seymour; Donna Hill; Johnsie Lang; Elizabeth I. Hamelin; Rudolph C. Johnson. 2018. "Quantification of Microcystin-LR in Human Urine by Immunocapture Liquid Chromatography Tandem Mass Spectrometry." Chemical Research in Toxicology 31, no. 9: 898-903.