Determination of total uranium and uranium isotope ratios in human urine by ICP-MS:results of an interlaboratory study

2015 ◽  
Vol 30 (1) ◽  
pp. 126-138 ◽  
Author(s):  
John G. Arnason ◽  
Christine N. Pellegri ◽  
Patrick J. Parsons
Keyword(s):  
Reference Materials ◽  
Human Urine ◽  
Isotope Ratios ◽  
Uranium Isotope ◽  
Interlaboratory Study

Interlaboratory performance is reported for nine participants analyzing six well-characterized urine reference materials supplemented with 234U, 235U, 236U, and 238U.

scholarly journals Validation of an Immunoassay for Detection and Quantitation of a Genetically Modified Soybean in Food and Food Fractions Using Reference Materials: Interlaboratory Study

2000 ◽  
Vol 83 (4) ◽  
pp. 919-928 ◽  
Author(s):  
Markus Lipp ◽  
Elke Anklam ◽  
James W Stave ◽  
J Bahrs-Windsberger ◽  
M T Barreto Crespo ◽  
...  
Keyword(s):  
Reference Materials ◽  
Genetically Modified ◽  
Quantitative Result ◽  
Interlaboratory Study ◽  
Food Matrix ◽  
Genetically Modified Soybean ◽  
Soybean Powder ◽  
Genetically Modified Soybeans ◽  
Specific Food

Abstract An immunoassay for detection of a specific genetically modified soybean (Roundup-Ready®) was validated on dried soybean powder in an interlaboratory study. Different percentages of genetically modified soybeans in nonmodified soybean matrix were evaluated in a blind study. Thirty-eight laboratories from 13 countries participated. The immunoassay was evaluated for 2 endpoints: (1) To give a semiquantitative result, i.e., determination of a given sample above or below a given threshold, or (2) to compute a quantitative result, i.e., percentage of genetically modified soybeans in the sample. Semiquantitative results showed that a given sample which contained <2% genetically modified soybeans was identified as below 2% with a 99% confidence level. Quantitative use of the assay resulted in a repeatability (r) and reproducibility (R) that were computed to be RSDr = 7% and RSDR = 10%, respectively, for a sample containing 2% genetically modified soybeans. Application of this method depends on availability of appropriate reference materials for a specific food matrix. Only matrix-matched reference materials can be used for analysis of food or food fractions.

Inductively Coupled Plasma-Mass Spectrometric Determination of Iodine in Food Using Tetramethyl Ammonium Hydroxide Extraction—Results from a U.S. Food and Drug Administration Level 3 Interlaboratory Study

2019 ◽  
Vol 102 (4) ◽  
pp. 1194-1198 ◽  
Author(s):  
Todor I Todorov ◽  
Yunseol Kim ◽  
Jennifer Fong Sam ◽  
Erica Mote ◽  
Cynthia C Smith ◽  
...  
Keyword(s):  
Drug Administration ◽  
Reference Materials ◽  
Inductively Coupled Plasma ◽  
Food And Drug Administration ◽  
Ammonium Hydroxide ◽  
Mass Spectrometric ◽  
Interlaboratory Study ◽  
Inductively Coupled ◽  
Tetramethyl Ammonium Hydroxide

Abstract Background: The performance of U.S. Food and Drug Administration (FDA) Elemental Analysis Manual (EAM) 4.13 method (Inductively Coupled Plasma-Mass Spectrometric Determination of Iodine in Food Using Tetramethyl Ammonium Hydroxide Extraction) was tested in an interlaboratory study. Objective: The aim of the study is to demonstrate that the FDA EAM method 4.13 is applicable for the analysis of food and multivitamins. Methods: Six collaborators participated in the study using four different models of inductively coupled plasma-mass spectrometry instruments. The method evaluation included determination of the limits of detection and quantification, analysis of National Institute of Standards and Technology standard reference materials (SRMs), unknown samples, blinded SRMs, and fortified analytical portions by all six collaborators. The samples were chosen to represent all sectors of the AOAC food triangle and additionally included pet food and multivitamin tablets. Results: The repeatability and reproducibility ranges were 1.8–11.4% and 3.6–13.7%, respectively; the calculated HorRat values were in the 0.17–1.18 range; and 174 of 175 SRM analyses had z-scores <2 and fortified analytical portion samples with recoveries of 102–105%, indicating acceptable method performance. Conclusions: The study supports a Level Three Multilaboratory Validation according to FDA Food and Veterinary Program Guidelines performed by six collaborators using six certified reference materials and nine unknown samples. Highlights: The method is applicable for quantification of the total extractable iodine in food and multivitamin dietary supplements.

scholarly journals Characterization of a series of absolute isotope reference materials for magnesium: ab initio calibration of the mass spectrometers, and determination of isotopic compositions and relative atomic weights

2016 ◽  
Vol 31 (7) ◽  
pp. 1440-1458 ◽  
Author(s):  
Jochen Vogl ◽  
Björn Brandt ◽  
Janine Noordmann ◽  
Olaf Rienitz ◽  
Dmitriy Malinovskiy
Keyword(s):  
Ab Initio ◽  
Reference Materials ◽  
Isotope Ratios ◽  
Mass Spectrometers ◽  
Isotopic Compositions

Three different MC-ICPMS instruments were calibrated by means of synthetic isotope mixtures to enable absolute Mg isotope ratios with expanded uncertainties of ≤0.15‰.

Sign in / Sign up

Export Citation Format

Share Document