A5079230587- Vitamin D Research Studies
- Effects and risks of endocrine disrupting chemicals
- Advanced Chemical Sensor Technologies
- Muscle metabolism and nutrition
- Phytoestrogen effects and research
- Pesticide Residue Analysis and Safety
- Analytical Chemistry and Chromatography
- Mass Spectrometry Techniques and Applications
- Diet, Metabolism, and Disease
- Healthcare cost, quality, practices
- Food Safety and Hygiene
- Microfluidic and Capillary Electrophoresis Applications
- Biosimilars and Bioanalytical Methods
- Analytical Methods in Pharmaceuticals
- Analytical chemistry methods development
- Metabolomics and Mass Spectrometry Studies
- Health Sciences Research and Education
- Nutritional Studies and Diet
- Cardiovascular and exercise physiology
- Quality and Safety in Healthcare
- Vitamin C and Antioxidants Research
- Phosphorus and nutrient management
- Seaweed-derived Bioactive Compounds
- Plant-Derived Bioactive Compounds
- Hormonal and reproductive studies
National Institute of Standards and Technology
2015-2025
National Institute of Standards
2018-2023
NOAA Chemical Sciences Laboratory
2017-2023
Material Measurement Laboratory
2015-2021
Pfizer (United States)
2016
Chemi (Italy)
2016
Tampa Bay Research Institute
2016
Covance (United States)
2016
Herbalife (Australia)
2016
National Sanitation Foundation International
2016
Abstract Until recently, the Vitamin D External Quality Assessment Scheme (DEQAS) assessed performance of various assays for determination serum total 25-hydroxyvitamin [25(OH)D] by using a consensus mean based on all-laboratory trimmed (ALTM) approximately 1000 participants' results. Since October 2012, National Institute Standardsand Technology (NIST), as part Standardization Program, has participated in DEQAS analyzing quarterly sample sets an isotope dilution LC-tandem MS (ID LC-MS/MS)...
Abstract Commutability is where the measurement response for a reference material (RM) same as an individual patient sample with concentration of analyte measured using two or more systems. Assessment commutability essential when RM used in calibration hierarchy to ensure that clinical measurements are comparable across different procedures and at times. The three new Standard Reference Materials ® (SRMs) determining serum total 25-hydroxyvitamin D [25(OH)D], defined sum 2 [25(OH)D ] 3 ],...
Abstract Since 2005, the National Institute of Standards and Technology (NIST) has collaborated with Institutes Health (NIH), Office Dietary Supplements (ODS) to improve quality measurements related human nutritional markers vitamin Dstatus. In support NIH-ODS Vitamin D Initiative, including Standardization Program (VDSP), NIST efforts have focused on (1) development validated analytical methods, reference measurement procedures (RMPs); (2) Standard ReferenceMaterials (SRMs); (3) value...
Polypropylene (PP) capillary-channeled polymer (C-CP) fibers are applied for solid phase extraction (SPE) of proteins from aqueous buffer solutions using a micropipette tip-based format. A process was developed in which centrifugation is used as the moving force solution passage loading/washing steps instead previously employed manual aspiration. The complete procedure requires ~15 minutes, with number samples run parallel limited only by capacity centrifuge. method performance evaluated...
Increased consumption of dietary supplements brings about important requirements analytical methods to allow accurate and precise measurements the chemical composition these botanical materials. Presented here is isoflavone content in proposed National Institute Standards Technology standard reference materials (SRMs) determined by LC-particle beam/electron ionization MS. Botanical (soy, red clover, kudzu) are characterized for a suite five isoflavones (puerarin, daidzein, genistein,...
Presented here is a novel in-line solid phase extraction (SPE) method utilizing capillary-channeled polymer (C-CP) fiber microcolumn prior to introduction an electrospray ionization (ESI) source. The high permeability of the allows for operation under syringe pump or HPLC driven flow, ultimately providing greater mass spectral clarity and accurate molecular weight determinations different protein/buffer combinations. Studies presented focus on desalting several target proteins from standard...
Six laboratories associated with the Vitamin D Standardization Program (VDSP) participated in an interlaboratory comparison of LC tandem MS (MS/MS) methods for determination 24,25-dihydroxyvitamin D3 [24,25(OH)2D3] human serum. The analyzed two different serum-based Standard Reference Materials (SRMs) intended use 25-hydroxyvitamin and 30 samples from External Quality Assessment Scheme (DEQAS). All laboratory 24,25(OH)2D3 were based on isotope dilution LC-MS/MS; three used derivatization...
Abstract The characterization of marker components in botanical materials is a challenging task, and the increased consumption botanicals dietary supplements demands greater understanding associated health benefits risks. In order to successfully acquire compare clinical results correlate trends, accurate, precise, validated methods analysis must be developed. Presented here development quantitative method for determination soy isoflavones (daidzin, glycitin, genistin, daidzein, genistein)...
Abstract Objectives Matrix differences among serum samples from non-pregnant and pregnant patients could bias measurements. Standard Reference Material 1949, Frozen Human Prenatal Serum, was developed to provide a quality assurance material for the measurement of hormones nutritional elements throughout pregnancy. Methods Serum women in each trimester were bottled into four levels based on pregnancy status trimester. Liquid chromatography tandem mass spectrometry (LC-MS/MS) methods applied...