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1.
The complexity of different quality standards can, in principle, be covered by different approaches and strategies. In-depth
process mapping of quality control (QC) work streams was used by the analytical laboratories of Lonza AG to show up the principle
differences in being compliant to different quality systems. The results identified two main drivers for all necessary actions:
process-related activities and infrastructure-related activities. In addition, a clear indication of the economic impact of
these driving forces was gained, which led the laboratories to decide on a process-oriented approach. This approach has the
advantage of being able to reflect the different demands of different quality assurance (QA) regulations within the same QC
organizational structure. Following the process helps avoid unnecessary efforts in analytical work and represents a very economical
approach, at the same time, providing high flexibility to react to different QA or customer demands.
Received: 5 July 2002 Accepted: 12 November 2002
Acknowledgements The process-oriented approach resulted from many, very challenging discussions for which I would like to thank the staff
of my organization (Analytics & QC), especially, the QA staff and the LIMS team.
Presented at Analytica Conference, 23–26 April 2002, Munich, Germany
Correspondence to B. Ciommer 相似文献
2.
In this paper, the three-dimensional (3D) interfacial fracture is analyzed in a one-dimensional (1D) hexagonal quasicrystal (QC) coating structure under mechanical loading. A planar interface crack with arbitrary shape is studied by a displacement discontinuity method. Fundamental solutions of interfacial concentrated displacement discontinuities are obtained by the Hankel transform technique, and the corresponding boundary integral-differential equations are constructed with the superposition principle. Green’s functions of constant interfacial displacement discontinuities within a rectangular element are derived, and a boundary element method is proposed for numerical simulation. The singularity of stresses near the crack front is investigated, and the stress intensity factors (SIFs) as well as energy release rates (ERRs) are determined. Finally, relevant influencing factors on the fracture behavior are discussed. 相似文献
3.
M.C. Menet C.H. Cottart M. Taghi V. Nivet-Antoine D. Dargère F. Vibert O. Laprévote J.-L. Beaudeux 《Analytica chimica acta》2013
Resveratrol is a polyphenol that has numerous interesting biological properties, but, per os, it is quickly metabolized. Some of its metabolites are more concentrated than resveratrol, may have greater biological activities, and may act as a kind of store for resveratrol. Thus, to understand the biological impact of resveratrol on a physiological system, it is crucial to simultaneously analyze resveratrol and its metabolites in plasma. This study presents an analytical method based on UHPLC-Q-TOF mass spectrometry for the quantification of resveratrol and of its most common hydrophilic metabolites. The use of 13C- and D-labeled standards specific to each molecule led to a linear calibration curve on a larger concentration range than described previously. The use of high resolution mass spectrometry in the full scan mode enabled simultaneous identification and quantification of some hydrophilic metabolites not previously described in mice. In addition, UHPLC separation, allowing run times lower than 10 min, can be used in studies that requiring analysis of many samples. 相似文献
4.
Badol C Borbon A Locoge N Léonardis T Galloo JC 《Analytical and bioanalytical chemistry》2004,378(7):1815-1827
An automated system for the monitoring of volatile organic compound (VOC) ozone precursors in ambient air is described. The measuring technique consists of subambient preconcentration on a cooled trap followed by thermal desorption and GC/FID analysis. First, the technical development, which permits detection limits below 0.05 ppbv to be reached, proceeded in two steps: (1) the determination of optimum sampling parameters (trap composition and conditioning, outlet split, desorption temperature); (2) the development of a reliable calibration method based on a highly accurate standard. Then, a 4-year field application of the hourly measuring chain was carried out at two urban sites. On the one hand, quality control procedures provided the best VOC identification (peak assignment) and quantification (reproducibility, blank system control). On the other hand, the success and performances of the routine experience (88% of the measurements covered more than 40 target compounds) indicated the high quality and suitability of the instrumentation which is actually applied in several French air quality monitoring networks. Finally, an example of data analysis is presented. Data handling identified important organic compound sources other than vehicle exhaust. 相似文献
5.
Shah Hussain Cornelia Pezzei Yüksel Güzel Matthias Rainer Christian W. Huck Günther K. Bonn 《Analytica chimica acta》2014
An efficient blood plasma clean-up method was developed, where methanol protein precipitation was applied, followed by zirconium silicate assisted exclusion of residual proteins. A strong binding of zirconium (IV) silicate to the proteins enabled the elimination of remaining proteins after solvent deproteinization through a rapid solid-phase extraction (SPE) procedure. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/TOF MS) was used for monitoring the proteins during clean-up practice applied to human plasma samples. The proteins were quantified by colorimetric detection using the bicinchoninic acid (BCA) assay. The presented analytical strategy resulted in the depletion of >99.6% proteins from human plasma samples. Furthermore, high-performance liquid chromatography hyphenated to diode-array and electrospray ionization mass spectrometric detection (HPLC–DAD/ESI MS) was applied for qualitative and quantitative analysis of the caffeoylquinic acids (CQAs) and their metabolites in human plasma. The procedure demonstrated high recoveries for the standard compounds spiked at different concentrations. Cynarin and chlorogenic acid were recovered in the range of 81–86% and 78–83%, respectively. Caffeic acid was extracted in the excess of 89–92%, while ferulic acid and dihydroxyhydrocinnamic acid showed a recovery of 87–91% and 92–95%, respectively. The method was partially validated in accordance with FDA-Industry Guidelines for Bioanalytical Method Validation (2001). The presented scheme improves the clean-up efficacy of the methanol deproteinization, significantly reduces the matrix effects and provides a great analytical tool for the isolation of small molecules from human plasma. 相似文献
6.
Analytical methods for the analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are widely available
and are the result of a vast amount of environmental analytical method development and research on persistent organic pollutants
(POPs) over the past 30–40 years. This review summarizes procedures and examines new approaches for extraction, isolation,
identification and quantification of individual congeners/isomers of the PCBs and OCPs. Critical to the successful application
of this methodology is the collection, preparation, and storage of samples, as well as specific quality control and reporting
criteria, and therefore these are also discussed. With the signing of the Stockholm convention on POPs and the development
of global monitoring programs, there is an increased need for laboratories in developing countries to determine PCBs and OCPs.
Thus, while this review attempts to summarize the current best practices for analysis of PCBs and OCPs, a major focus is the
need for low-cost methods that can be easily implemented in developing countries. A “performance based” process is described
whereby individual laboratories can adapt methods best suited to their situations. Access to modern capillary gas chromatography
(GC) equipment with either electron capture or low-resolution mass spectrometry (MS) detection to separate and quantify OCP/PCBs
is essential. However, screening of samples, especially in areas of known use of OCPs or PCBs, could be accomplished with
bioanalytical methods such as specific commercially available enzyme-linked immunoabsorbent assays and thus this topic is
also reviewed. New analytical techniques such two-dimensional GC (2D-GC) and “fast GC” using GC–ECD may be well-suited for
broader use in routine PCB/OCP analysis in the near future given their relatively low costs and ability to provide high-resolution
separations of PCB/OCPs. Procedures with low environmental impact (SPME, microscale, low solvent use, etc.) are increasingly
being used and may be particularly suited to developing countries.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
7.
8.
Zhiyuan Tang Mengqiu Wu Yingchun Li Xiao Zheng Huiying Liu Xuefang Cheng Lin Xu Guangji Wang Haiping Hao 《Analytica chimica acta》2013
NAD(P)H:quinone oxidoreductase 1 (NQO1, DT-diaphorase) is a prognostic biomarker and a potential therapeutic target for various tumors. Therefore, it is of significance to develop a robust method for the absolute quantification of NQO1. This study aimed to develop and validate a LC–MS/MS based method and to test the appropriateness of using non-isotopic analog peptide as the internal standard (IS) by comparing with a stable isotope labeled (SIL) peptide. The chromatographic performance and mass spectra between the selected signature peptide of NQO1 and the non-isotopic peptide were observed to be very similar. The use of the two internal standards was validated appropriate for the absolute quantification of NQO1, as evidenced by satisfactory validation results over a concentration range of 1.62–162 fmol μL−1. This method has been successfully applied to the absolute quantification of NQO1 expression in various tumor cell lines and tissues. NQO1 expression in human tumor tissues is much higher than that in the neighboring normal tissues in both the cases of lung and colon cancer. The quantitative results obtained from the isotopic and non-isotopic methods are quite similar, further supporting that the use of non-isotopic analog peptide as internal standard is appropriate and feasible for the quantification of NQO1. By comparing with a classical isotopic IS, the present study indicates that the use of a non-isotopic peptide analog to the proteotypic peptide as the internal standard can get equal accuracy and preciseness in measuring NQO1. The universal applicability of the non-isotopic IS approach for the quantification of proteins warrants further research. 相似文献
9.
Long Yuan Li Ma Lisa Dillon R. Marcus Fancher Huadong Sun Mingshe Zhu Lois Lehman-McKeeman Anne-Françoise Aubry Qin C. Ji 《Analytica chimica acta》2016
LC-MS/MS has been widely applied to the quantitative analysis of tissue samples. However, one key remaining issue is that the extraction recovery of analyte from spiked tissue calibration standard and quality control samples (QCs) may not accurately represent the “true” recovery of analyte from incurred tissue samples. This may affect the accuracy of LC-MS/MS tissue bioanalysis. Here, we investigated whether the recovery determined using tissue QCs by LC-MS/MS can accurately represent the “true” recovery from incurred tissue samples using two model compounds: BMS-986104, a S1P1 receptor modulator drug candidate, and its phosphate metabolite, BMS-986104-P. We first developed a novel acid and surfactant assisted protein precipitation method for the extraction of BMS-986104 and BMS-986104-P from rat tissues, and determined their recoveries using tissue QCs by LC-MS/MS. We then used radioactive incurred samples from rats dosed with 3H-labeled BMS-986104 to determine the absolute total radioactivity recovery in six different tissues. The recoveries determined using tissue QCs and incurred samples matched with each other very well. The results demonstrated that, in this assay, tissue QCs accurately represented the incurred tissue samples to determine the “true” recovery, and LC-MS/MS assay was accurate for tissue bioanalysis. Another aspect we investigated is how the tissue QCs should be prepared to better represent the incurred tissue samples. We compared two different QC preparation methods (analyte spiked in tissue homogenates or in intact tissues) and demonstrated that the two methods had no significant difference when a good sample preparation was in place. The developed assay showed excellent accuracy and precision, and was successfully applied to the quantitative determination of BMS-986104 and BMS-986104-P in tissues in a rat toxicology study. 相似文献
10.