Authors:Katalin Ferenczi-Fodor, Bernd Renger, and Zoltán Végh
Analytical procedures to be used in pharmaceutical quality control have to be validated strictly in accordance with highly formalized standards and guidance. Manuscripts submitted for publication presenting new procedures must therefore describe the corresponding validation characteristics and the validation approach and procedure accordingly. Interestingly, many of these manuscripts and — what is worse — already published (and therefore accepted) articles in various periodicals are characterized by several typical methodological failures and misconceptions — even though authors have regularly been informed of such mistakes in the hope they can be avoided. The corresponding ICH guideline seems to be well-known, and is frequently cited in these manuscripts, but to some extent is not fully understood and is even partially neglected. In this paper the authors present a collection of typical failures, misconceptions, and misleading data captured as reviewers and readers of published articles over the last two years, thus giving a survey of the most frequent problems of TLC/HPTLC validation. Moreover, the authors provide a list of references describing optimum approaches to validation of specific TLC/HPTLC procedures. We suggest these are followed in addition to the general concepts of the ICH guideline.
Authors:Shmuel Yariv, Mikhail Borisover, and Isaak Lapides
-base drilling mud, homogenizing fillers in the plastic industry and for the purpose of gelling of various organic liquids. They are also used in cleaning operations of drainage wastewater, oil-spill, and so on. This manuscript will summarize some of the basic
This manuscript presents a typical analytical application of ion-exchange resins in mixed solvent media for the separation
and determination of a number of trace elements in high purity scandium, where direct instrumental approach for its characterization/analysis
is difficult. This work demonstrated, how a few beads of ion exchange resin could be effectively used for the pre-concentration
of the separated trace elements for their determination using neutron activation analysis (NAA). Radiotracer and standard
addition methods were used for validation.
In this short communication, a recent article published in the Journal of Thermal Analysis and Calorimetry, which presents
an erroneous conclusion based on incorrect calculations, is critically discussed. Since the observations made in that report
are based on part of the content of a publication of my authorship, trying to reject some expressions I presented, obviously
it came to my attention. This brief note emphasizes that some of the arguments used and the main conclusion stressed in the
manuscript under discussion are wrong and must be dismissed.
Authors:J. Ferrero, C. Roldán, E. Navarro, M. Ardid, M. Marzal, J. Almirante, P. Ineba, J. Vergara, and C. Mata
We present examples of the application of the X-ray fluorescence (XRF) to the study of the artistic and cultural patrimony
of the Comunidad Valenciana in the following areas: a) Valencian paintings of the XV and XVI centuries; b) silver ornaments
coming from Iberian towns (s. III b.C.); c) ink and paper samples in manuscripts and engravings of the XVII and XIX centuries.
The non destructive analyses are carried out “in situ” using a XRF system that consists of a tube of X-rays of 50 kV and 1
mA, and a detector of Si(Li) with an energy resolution 140 eV (FWHM at 5.9 keV).
Authors:K. Anderson, K. Jarman, M. Mann, D. Pfund, and R. Runkle
This manuscript presents a method for categorizing gamma-ray spectra as indicative of benign or threat sources. Reported here
is a method of spectral comparison ratios (SCR), which is useful in the targeted detection of specific gamma-ray signature
classes. SCRs discriminate between benign and target sources by comparing counts in broad energy bins that are pre-determined
using statistical discrimination criteria. The integral component of the SCR method is the location and interdependence of
the energy bins, and this work discusses the statistical methods used for choosing their locations along with decision criteria
that maximally separate targets from benign sources.
Authors:R. Zeisler, S. B. Clark, S. J. Parry, G. R. Choppin, S. B. Clark, P. R. Danesi, S. J. Parry, M. Rossbach, C. Williamson, Zhifang Chai, R. Zeisler, S. J. Parry, and S. F. Heller- Zeisler
Since the 1970's, concern about the training of radiochemists in the US has been increasing along with the age of nuclear work force, while the number of academic institutions offering undergraduate courses and the number of radiochemistry faculty has been steadily decreasing. To address this problem, a summer program has been offered through the American Chemical Society to undergraduates since 1984. Students compete nationally for this opportunity, and those selected receive a 3,000 stipend. In addition, all other expenses are paid. In this manuscript, the curriculum is described, along with the need for additional training programs and their impact.