Comments on the Note on “Thermodynamic temperature differences from the ITS-90 for the correction of thermodynamic property data” by F. Pavese,P. Ciarlini,and P.P.M. Steur by J. Fischer,Chairman of WG4 of CCT

These are comments to a note from J. Fischer in publication.     

Cross-validation and evaluation of the performance of methods for the elemental analysis of forensic glass by μ-XRF, ICP-MS, and LA-ICP-MS

Elemental analysis of glass was conducted by 16 forensic science laboratories, providing a direct comparison between three analytical methods [micro-x-ray fluorescence spectroscopy (μ-XRF), solution analysis using inductively coupled plasma mass spectrometry (ICP-MS), and laser ablation inductively coupled plasma mass spectrometry]. Interlaboratory studies using glass standard reference materials and other glass samples were designed to (a) evaluate the analytical performance between different laboratories using the same method, (b) evaluate the analytical performance of the different methods, (c) evaluate the capabilities of the methods to correctly associate glass that originated from the same source and to correctly discriminate glass samples that do not share the same source, and (d) standardize the methods of analysis and interpretation of results. Reference materials NIST 612, NIST 1831, FGS 1, and FGS 2 were employed to cross-validate these sensitive techniques and to optimize and standardize the analytical protocols. The resulting figures of merit for the ICP-MS methods include repeatability better than 5 % RSD, reproducibility between laboratories better than 10 % RSD, bias better than 10 %, and limits of detection between 0.03 and 9 μg g^?1 for the majority of the elements monitored. The figures of merit for the μ-XRF methods include repeatability better than 11 % RSD, reproducibility between laboratories after normalization of the data better than 16 % RSD, and limits of detection between 5.8 and 7,400 μg g^?1. The results from this study also compare the analytical performance of different forensic science laboratories conducting elemental analysis of glass evidence fragments using the three analytical methods.

Note on “Thermodynamic temperature differences from the ITS-90 for the correction of thermodynamic property data” by F. Pavese,P. Ciarlini,and P.P.M. Steur [1]

A recent paper by Pavese et al. presents formulas for calculating the differences (T ? T₉₀) between temperatures measured on the internationally recognized temperature scale, ITS-90 and the thermodynamic temperature.However, there has been a systematic, international process in place to critically review the differences (T ? T₉₀) and to disseminate the results in a convenient form. The process was undertaken by Working Group 4 (WG4) at the request of the Consultative Committee for Thermometry. WG4 recently published the results of its review including consensus values of (T ? T₉₀) and a user-friendly, representation of (T ? T₉₀). One of the authors of the Pavese et al. paper is member of WG4.A multiplicity of representations of (T ? T₉₀) is an undesirable barrier to the exchange of thermodynamic information and obscures the status of temperature standards. Thus, WG4 recommends that the chemical thermodynamics community use the values (T ? T₉₀) and their polynomial representation as published in the WG4 paper.     

Differentiating the Gum Resins of Two Closely Related Indian Gardenia Species,G. gummifera and G. lucida,and Establishing the Source of “Dikamali” by TLC

JPC – Journal of Planar Chromatography – Modern TLC -