Key comparison CCQM-K45: Sn in tomato paste: final report

Briche, Céline S. J. Wolff; Holcombe, Gill; Sargent, Mike

doi:10.1088/0026-1394/43/1a/08014

Cited by 5 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The final report of CCQM-K45 [ 36 ] explains that UME deviated significantly from the protocol, and for this reason their result was excluded from the calculation of the KCRV. The KCRV was the simple average of the values measured by the other four participants, 227.1 mg / kg, and the associated standard uncertainty was 1.2 mg / kg.…”

Section: Examplesmentioning

confidence: 99%

“…The final report appears to recognize implicitly that a weighted average might have been preferable (the largest reported uncertainty was 4.3 times larger than the smallest reported uncertainty), but it points out that (1) "KRISS used a coverage factor equal to 2.45, which indicates only 6 degrees of freedom. As a result, the weighted mean is not considered the best estimate of the KCRV, as all results do not have sufficient degrees of freedom," and then it adds that (2) "as only 4 values can be used to calculate the KCRV, the median is also not considered the best estimate of the KCRV" [ 36, p . 5 ].…”

Section: Examplesmentioning

confidence: 99%

See 1 more Smart Citation

Decision Tree for Key Comparisons

Possolo

Koepke

Newton

2021

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

This contribution describes a Decision Tree intended to guide the selection of statistical models and data reduction procedures in key comparisons (KCs). The Decision Tree addresses a specific need of the Inorganic Analysis Working Group (IAWG) of the Consultative Committee (CC) for Amount of Substance, Metrology in Chemistry and Biology (CCQM), of the International Committee for Weights and Measures (CIPM), and it is likely to address similar needs of other working groups and consultative committees. Because the portfolio of KCs previously organized by the CCQM-IAWG affords a full range of opportunities to demonstrate the capabilities of the Decision Tree, the majority of the illustrative examples of application of the Decision Tree are from this working group. However, the Decision Tree is widely applicable in other areas of metrology, as illustrated in examples of application to measurements of radionuclides and of the efficiency of a thermistor power sensor. The Decision Tree is intended for use after choices will have been made about the measurement results that qualify for inclusion in the calculation of the key comparison reference value (KCRV), and about the measurement results for which degrees of equivalence should be produced. Both these choices should be based on substantive considerations, not on purely statistical criteria. However, the Decision Tree does not require that the measurement results selected for either purpose be mutually consistent. The Decision Tree should be used as a guide, not as the sole and autonomous determinant of the model that should be selected for the measurement results obtained in a KC, or of the procedure that should be employed to reduce these results. The scientists running the KCs ultimately have the freedom and responsibility to make the corresponding choices that they deem most appropriate and that best fit the purpose of each KC. The Decision Tree involves three statistical tests, and comprises five terminal leaves, which correspond to as many alternative ways in which the KCRV, its associated uncertainty, and the degrees of equivalence (DoEs) may be computed. This contribution does not purport to suggest that any of the KCRVs, associated uncertainties, or DoEs, presented in previously approved final reports issued by working groups of the CCs should be modified. Neither do the alternative results question existing, demonstrated calibration and measurement capabilities (CMCs), nor do they support any new CMCs.

show abstract

Section: Examplesmentioning

confidence: 99%

Section: Examplesmentioning

confidence: 99%

Decision Tree for Key Comparisons

Possolo

Koepke

Newton

2021

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

show abstract

“…Additionally, and in order to establish the qualities of our in-house reference materials, a comparison was made with a similar reference material used in CCQM-K108 37 and CCQM-K145 38 comparisons, which have a reported relative uncertainty for homogeneity between 0.81 and 1.6%. 37,39 These values are certainly lower than our iHRMs homogeneity uncertainty, but not so much and not always, see Figure 1. Then, our developed iHRMs are suitable for quality control in a routine or regulatory laboratory.…”

Section: Homogeneity Test For the Pineapple Ihrmsmentioning

confidence: 51%

Quantification of Arsenic, Cadmium, Mercury and Lead in Pineapple: Method Development, Validation and Evaluation of In-House Reference Materials

Garzón

Ahumada²,

Gamba³

et al. 2020

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

A method for quantification of arsenic, cadmium, mercury, and lead in pineapple using inductively coupled plasma-mass spectrometry (ICP-MS) was developed, validated, and used to test the homogeneity and stability of in-house reference materials. The method was tested at the regulation levels given by the Food and Agriculture Organization of the United Nations (FAO, 100 µg kg −1). The mineralization conditions of the samples, in a microwave oven, were improved throughout the study of HNO 3 and H 2 O 2 concentrations, sample weight, time, and temperatures. The calibration was made by a gravimetric standard addition method with internal standard correction. The validation parameters were accuracy (trueness as recovery, between 97-112%, and precision as repeatability, below 12%), limits of detection (As 14.2, Cd 1.5, Hg 21.9, and Pb 5.4 µg kg −1 measured in pineapple), linearity and selectivity. The in-house material was lyophilized or dried in an oven. The best way to dry it was by the oven process because it has the lowest uncertainty.

show abstract

“…Even though there are standards and guides such as ISO/IEC 17025 and the Eurachem Guides about the requirements, differences in how these are applied in analytical laboratories can lead to bias in the results. In the elemental analysis of tomato paste, results have been inconsistent between laboratories in proficiency testing and the consensus values include biases compared to the reference values from the National Metrology Institute . In this context, a good practice for quality assurance is the use of certified reference materials (CRMs).…”

Section: Introductionmentioning

confidence: 99%

“…In the elemental analysis of tomato paste, results have been inconsistent between laboratories in proficiency testing and the consensus values include biases compared to the reference values from the National Metrology Institute. 18 In this context, a good practice for quality assurance is the use of certified reference materials (CRMs). According to ISO/IEC 17025, if a matrix matched reference material is available, the use of it is strongly recommended for method validation and quality control.…”

Section: Introductionmentioning

confidence: 99%

Development of a Paste‐type Certified Reference Material of Tomato for Elemental Analysis: Certification and Long‐term Stability Study

Choi

Hwang

Yim

et al. 2017

Bulletin Korean Chem Soc

View full text Add to dashboard Cite

A paste‐type certified reference material (CRM) of tomato was developed for accurate elemental analysis of canned foods. Accurate mass fractions of cadmium (Cd), lead (Pb), and tin (Sn) in the tomato paste CRM were determined by isotope dilution inductively coupled plasma mass spectrometry. The certified values and their expanded uncertainties (k=2 at approximately 95% level of confidence) for Cd, Pb, and Sn were (0.297 ± 0.015) mg/kg, (0.213 ± 0.010) mg/kg, and (221.2 ± 9.5) mg/kg, respectively. Homogeneity of the CRM was 0.3%, 1.8%, and 0.2% for Cd, Pb, and Sn, respectively, which were estimated using the relative standard deviation of the measurement results of 10 separate sample bottles from one batch of the CRM. Major contributions to the measurement uncertainties for Cd and Sn were the uncertainties of the isotope ratios of Cd and Sn in the sample and the elemental standards. The uncertainty for Pb was mainly affected by sample homogeneity. Stability tests were conducted for 6 and 12 months at −20, 4, and 25°C, and the storage temperature for the CRM was determined to be −20°C. To investigate long‐term storage, the mass fractions of Cd, Pd, and Sn in the CRM were re‐determined after storage for 7 years. The results were in good agreement with the certified results implying that this CRM is stable for 7 years if kept at an appropriate storage condition with vacuum packaging the amber glass bottles in aluminum‐coated polymer bag.

show abstract

Key comparison CCQM-K45: Sn in tomato paste: final report

Cited by 5 publications

References 0 publications

Decision Tree for Key Comparisons

Decision Tree for Key Comparisons

Quantification of Arsenic, Cadmium, Mercury and Lead in Pineapple: Method Development, Validation and Evaluation of In-House Reference Materials

Development of a Paste‐type Certified Reference Material of Tomato for Elemental Analysis: Certification and Long‐term Stability Study

Contact Info

Product

Resources

About