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Search Publications by: Grace Hahm (Assoc)

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Displaying 1 - 7 of 7

Assessment of Serum Total 25-Hydroxyvitamin D Assays for Vitamin D External Quality Assessment Scheme (DEQAS) Materials Distributed at Ambient and Frozen Conditions

November 9, 2021
Author(s)
Johanna Camara, Christopher T. Sempos, Emma L. Williams, Graham D. Carter, Julia C. Jones, Carolyn Burdette, Grace Hahm, Federica Nalin, David L. Duewer, Adam J. Kuszak, J. M. Betz, Andrew Hoofnagle, Pierre Lukas, E. Cavalier, Ramon Durazo-Arvizu, P. M. Crump, Christian Popp, Christian Beckert, Glen Van Slooten, Patrick Gradon, Joelle Morgand, Sarah Paul, Bruno Emanuelli, Angelo Maggio, Fiona Ivison, Ralf Fischer, Jody M. van den Ouweland, Chung S. Ho, Emmett W. Law, Jean-Nicolas Simard, Renaud Gonthier, Brett Holmquist, Manisha S. Patwardhan, Marcelo C. Batista, Heather Pham, Sarah Meadows, Eugene Jansen, Dilshad A. Khan, Kimberly Robyak, Mark Kilbane, Neil Parker, Vincent Chen, Robert Fitzgerald, Sohail Mushtaq, Michael W. Clarke, Norma Breen, Christine Simpson, Stephen A. Wise
The Vitamin D External Quality Assessment Scheme (DEQAS) distributes human serum samples four times per year to over 1000 participants worldwide for the determination of total serum 25-hydroxyvitamin D [25(OH)D)]. These samples are stored at −40 °C prior

Certification of Standard Reference Material(R) 2386 Avocado Powder

October 20, 2021
Author(s)
Melissa M. Phillips, Laura J. Wood, George Caceres, Grace Hahm, Karen E. Murphy, Rick L. Paul, Benjamin Place, James H. Yen
The National Institute of Standards and Technology (NIST) recently released SRM 2386 Avocado Powder which has value assignment for over 70 analytes. This material has certified values assigned for 22 analytes and non-certified values assigned for 53

Certification of Standard Reference Materials(R) 2969 and 2970: Vitamin D Metabolites in Frozen Human Serum (Total 25-Hydroxyvitamin D Low Level) and (25-Hydroxyvitamin D2 High Level)

September 2, 2021
Author(s)
Grace Hahm, Michael Nelson, Johanna Camara, Blaza Toman
Standard Reference Materials (SRMs) 2969 and 2970 are intended for 1) use in validating methods for determining concentrations of 25-hydroxyvitamin D2 (25(OH)D2) and 25-hydroxyvitamin D3 (25(OH)D3) in human serum and plasma and 2) value assigning in house

Interlaboratory Comparison of 25-Hydroxyvitamin D Assays: Vitamin D Standardization Program (VDSP) Intercomparison Study 2 - Part 2 Immunoassays - Impact of 25 Hydroxyvitamin D2 and 24R,25-Dihydroxyvitamin D3 on Assay Performance

August 27, 2021
Author(s)
Stephen Wise, Johanna Camara, Carolyn Burdette, Grace Hahm, Federica Nalin, Adam Kuszak, Joyce Merkel, Ramon Durazo-Arvizu, Emma Williams, Christian Popp, Christian Beckert, Jan Schultess, Glen Van Slooten, Carole Tourneur, Camille Pease, Kavi Kaul, Alfredo Villarreal, Marcelo Batista, Heather Pham, Alex Bennett, Eugene Jansen, Dilshad Khan, Mark Kilbane, Patrick Twomey, James Freeman, Neil Parker, Sohail Mushtaq, Christine Simpson, Pierre Lukas, Etienne Cavalier, Christopher Sempos
An interlaboratory comparison study was conducted by the Vitamin D Standardization Program (VDSP) to assess the performance of immunoassays (Part 2) for the determination of serum total 25 hydroxyvitamin D [25(OH)D]. A set of 50 single-donor samples was

Interlaboratory Comparison of 25-Hydroxyvitamin D Assays: Vitamin D Standardization Program (VDSP) Intercomparison Study 2 - Part 1 Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS) Assays - Impact of 3-epi-25-Hydroxyvitamin D3

August 27, 2021
Author(s)
Stephen Wise, Johanna Camara, Carolyn Burdette, Grace Hahm, Federica Nalin, Adam Kuszak, Joyce Merkel, Ramon Durazo-Arvizu, Emma Walker, Andrew Hoofnagle, Fiona Ivison, Ralf Fischer, Jody van den Ouweland, Chung Ho, Emmet Law, Jean-Nicolas Simard, Renaud Gonthier, Brett Holmquist, Sarah Meadows, Lorna Cox, Kimberly Robyak, Michael Creer, Robert Fitzgerald, Michael Clarke, Norma Breen, Pierre Lukas, Etienne Cavalier, Christopher Sempos
An interlaboratory comparison study was conducted by the Vitamin D Standardization Program (VDSP) to assess the performance of liquid chromatography – tandem mass spectrometry (LC-MS/MS) assays used for the determination of serum total 25-hydroxyvitamin D

Assessment of Serum Total 25 Hydroxyvitamin D Assay Commutability of Standard Reference Materials and College of American Pathologists Accuracy Based Vitamin D (ABVD) Scheme and Vitamin D External Quality Assessment Scheme (DEQAS) Materials: Vitamin D Sta

July 1, 2021
Author(s)
Johanna Camara, Stephen A. Wise, Andrew Hoofnagle, Emma L. Williams, Graham D. Carter, Julia C. Jones, Carolyn Burdette, Grace Hahm, Federica Nalin, Adam J. Kuszak, Joyce M. Merkel, Ramon Durazo-Arvizu, Pierre Lukas, E. Cavalier, Christian Popp, Christian Beckert, Jan Schultess, Glen Van Slooten, Carole Tourneur, Camille Pease, Ravi Kaul, Alfredo Villarreal, Fiona Ivison, Ralf Fischer, Jody M. van den Ouweland, Chung S. Ho, Emmett W. Law, Jean-Nicolas Simard, Renaud Gonthier, Brett Holmquist, Marcelo C. Batista, Heather Pham, Alex Bennett, Sarah Meadows, Lorna Cox, Eugene Jansen, Dilshad A. Khan, Kimberly Robyak, Michael H. Creer, Mark Kilbane, Patrick J. Twomey, James Freeman, Neil Parker, Jinyun Yuan, Robert Fitzgerald, Sohail Mushtaq, Michael W. Clarke, Norma Breen, Christine Simpson, Christopher T. Sempos
An interlaboratory study was conducted through the Vitamin D Standardization Program (VDSP) to assess commutability of Standard Reference Materials® (SRMs) and proficiency testing/external quality assessment (PT/EQA) samples for determination of serum

Vitamin D Standardization Program (VDSP) intralaboratory study for the assessment of 25-hydroxyvitamin D assay variability and bias

May 17, 2021
Author(s)
Johanna Camara, Stephen Wise, Christopher T. Sempos, Pierre Lukas, Caroline LeGoff, Stephanie Peeters, Carolyn Burdette, Federica Nalin, Grace Hahm, Ramon Durazo-Arvizu, Adam J. Kuszak, Joyce M. Merkel, E. Cavalier
An intralaborabory comparison study to assess the performance of assays for the determination of serum total 25-hydroxyvitamin D [25(OH)D] was conducted in 2017 as part of the Vitamin D Standardization Program (VDSP). The intralaboratory study consisted of