Quality control and quality assurance aspects of the routine use of capillary electrophoresis for serum and urine proteins in clinical laboratories

Using capillary electrophoresis (CE) for serum protein electrophoresis, the quality of results begins with monitoring a well-functioning instrument, using scrupulously clean capillaries, well-calibrated methods as well as regular use of an internal quality control material. Quality assurance programs are available in countries such as Australia, United Kingdom, United States, and European countries such as Sweden and Germany. The present commercial control material that is available gives percentages of albumin, alpha 1, alpha 2, beta- and gamma-globulins, the gamma-component being of normal distribution, and not containing any monoclonal protein component. We feel that a quantitative commercial control material containing a monoclonal protein at decision level for treating myeloma patients would be beneficial to all laboratories as a serum protein electrophoresis control, whether the analysis is by CE or agarose gels. The same applies for control material for urinary protein electrophoresis.     

Quality assurance systems in research and routine analytical laboratories

In our article we explain the connections between the implementation of quality assurance (QA) in research and routine analytical laboratories. J. K. Taylor claims that QA in an analytical laboratory consists of two independent but closely related terms, quality control and quality assessment. If we construct the QA system according to his ideas, problems concerning quality can be solved with only one concept regardless of the type of analytical laboratory. Therefore there is no need to introduce new QA standards for research laboratories as suggested in some papers. In the routine laboratory quality control is more important, while in the research laboratory quality assessment is dominant.     

Quality assurance systems in research and routine analytical laboratories

 In our article we explain the connections between the implementation of quality assurance (QA) in research and routine analytical laboratories. J. K. Taylor claims that QA in an analytical laboratory consists of two independent but closely related terms, quality control and quality assessment. If we construct the QA system according to his ideas, problems concerning quality can be solved with only one concept regardless of the type of analytical laboratory. Therefore there is no need to introduce new QA standards for research laboratories as suggested in some papers. In the routine laboratory quality control is more important, while in the research laboratory quality assessment is dominant.

     

Analysis of doping control samples using supercritical fluid chromatography-tandem mass spectrometry: Ready for routine use

Supercritical fluid chromatography is proving to be a good separation and sample preparation tool for various analytical applications and, as such, has gained the attention of the anti-doping community. Here, the applicability of supercritical fluid chromatography hyphenated to tandem mass spectrometry for routine doping control analysis was tested. A multi-analyte method was developed to cover 197 drugs and metabolites that are prohibited in sport. More than 1000 samples were analyzed by applying a “dilute and inject” approach after hydrolysis of glucuronide metabolites. Additionally, a comparison with routinely used liquid chromatography-mass spectrometry was performed with 250 of the 1000 samples and a number of past positive anti-doping samples. It revealed some features where supercritical fluid chromatography-tandem mass spectrometry was found to be complementary or advantageous to liquid chromatography-mass spectrometry for anti-doping purposes, such as better retention of analytes that are poorly retained in reversed-phase liquid chromatography. Our results suggest that supercritical fluid chromatography-tandem mass spectrometry is sensitive (limit of detection <50% relevant minimum required performance level required by the World Anti-Doping Agency for anti-doping analysis), reproducible, robust, precise (analytes of interest area coefficient of variation <5%; retention time difference coefficient of variation <1%) and complementary to existing techniques currently used for routine analysis in the World Anti-Doping Agency accredited laboratories.     

Quality assurance in research laboratories

During the last decade, it has become increasingly important that researchers demonstrate that research is conducted to the highest standards. The implementation of quality assurance for research laboratories will enable all fields of research and development to be judged impartially. There are no specific standards for research laboratories but where possible, existing standards can be adapted. This review is structured around two approaches. The first considers research to be a logical extension of testing, and it is assumed that testing standards can be applied methodically to each step in a research project. The second advocates a flexible approach, with research-specific criteria for assessing quality. The important papers published on this topic have been reviewed. The conclusions are that the general quality management approach, encompassed by the ISO 9000 series of standards with the emphasis on customer satisfaction and ‘fitness for purpose’, is suitable for implementing quality assurance in research laboratories.     

Guidance for accredited laboratories on the use of computers

 We review the draft international standard ISO/IEC 17025 and the EA guidelines; and present the existing National Physical Laboratory publication “Software in scientific instruments” and the new Measurement System Validation Best Practice guide. Received: 2 November 1999 / Accepted: 29 January 2000     

Performance tests and internal quality control activities for the routine analytical use of composite electrodes

The use of a solid electrode in routine analytical work is proposed as a good alternative for electroanalytical detection. The performance of the electrode for oxidative voltammetry was studied for the model compound, catechol. Some theoretical aspects of the preparation and features of the PVC-graphite composite electrode are shown. A protocol has been described for its construction and general advice for the appropriate use. Quality control activities were designed to check the performance of the electrode. Received: 7 October 2000 Accepted: 19 July 2001     

Management of quality control in analytical laboratories

The sources of errors in the results of chemical analysis are classified. Methods for the on-line control of the precision and accuracy of analysis are briefly discussed and compared in order to reveal the types of sources of errors in the considered methods. Algorithms to estimate the quality of work of an analytical laboratory based on the statistical analysis of the summarized results of control obtained in a certain period of time are proposed.     

Quality control procedures for chloride and nitrate ions analysis in plant samples by ion chromatography

This paper describes useful procedures to monitor quality of chloride and nitrate ions analysis in plant samples by ion chromatography. The use of certified reference materials (CRMs) provided an efficient way to verify the accuracy of the method. Data generated by the method of analysis for chloride compared favourably with certified values. The quality system included also the systematic analysis of an internal reference sample in each batch of samples routinely analysed. The performance of the method, including extraction and measurement, over a period of 3 years was reported with control charts. The yearly variation coefficients were less than 6.5% for chloride and nitrate ions. Finally, the analytical method was evaluated through the participation of laboratory to an international proficiency testing scheme. Found results were not significantly different from published medians.     

AlanineESR Dosimetry system for routine use in radiation processing

A new alanine-polystyrene (PS) dosimeter prepared with simplified molding procedure and an automatic desk-top dose-reader of alanine dosimeter were developed for the purpose of routine use. Combination of these two allows us to apply a reliable alanine/ESR dosimetry system to routine dosimetric process control in industrial gamma radiation processing.     

A simple, practical methodology for routine VSMOW/SLAP normalization of water samples analyzed by continuous flow methods

Normalization of stable isotope data is important for meaningful inter-laboratory comparisons of data, especially for waters where there may be large natural variations in isotope ratios of oxygen and hydrogen. As a result, large, systematic errors may arise in continuous flow applications without correction, whereas normalization to the VSMOW/SLAP scale can facilitate inter-laboratory comparison and can be accomplished by a simple procedure in which secondary laboratory standards, carefully calibrated, are analyzed along with unknown samples. Delta values for these standards, as analyzed, are plotted against the calibrated values and a linear regression is performed. The resulting equation is applied to unknown samples to achieve the normalization. The one-sigma [1sigma] standard deviation for replicate samples by this normalization method using a Finnigan Gasbenchll should be 相似文献   

Quality assurance and quality control in forest soil analyses: a comparison between European soil laboratories

In transnational monitoring programmes, a balance between international reference methods, which improve spatial comparability, and national analysis methods that favour temporal comparability, by their use and testing over many years, needs to be sought. Prior to the next Pan-European Forest Soil Survey, a third interlaboratory comparison of soil analysis methods was organised. All participating laboratories were requested to use the same reference methods. Fifty-two soil laboratories from 27 European countries analysed a total of 48 soil parameters on three soil samples which were typical for European forest soils. The results of the statistical analysis showed a high interlaboratory and intralaboratory variability, especially for the acid oxalate extractions, particle size distribution, exchangeable elements and total carbonates. The intercomparability of the test results did not improve compared to the previous ring test. As the exercise aimed primarily at comparing the performance of the laboratories, it was not powerful enough to find cause–effect relationships between the meta information provided by the laboratories and the variability of the test results.

     

Quality assurance and quality control in forest soil analyses: a comparison between European soil laboratories

In transnational monitoring programmes, a balance between international reference methods, which improve spatial comparability, and national analysis methods that favour temporal comparability, by their use and testing over many years, needs to be sought. Prior to the next Pan-European Forest Soil Survey, a third interlaboratory comparison of soil analysis methods was organised. All participating laboratories were requested to use the same reference methods. Fifty-two soil laboratories from 27 European countries analysed a total of 48 soil parameters on three soil samples which were typical for European forest soils. The results of the statistical analysis showed a high interlaboratory and intralaboratory variability, especially for the acid oxalate extractions, particle size distribution, exchangeable elements and total carbonates. The intercomparability of the test results did not improve compared to the previous ring test. As the exercise aimed primarily at comparing the performance of the laboratories, it was not powerful enough to find cause–effect relationships between the meta information provided by the laboratories and the variability of the test results.     

The use of a simple backflush technology to improve sample throughput and system robustness in routine gas chromatography tandem mass spectrometry analysis of doping control samples

A simple, low cost system for the backflushing of capillary gas chromatography (GC) columns has been investigated and integrated into a method for the detection of anabolic steroids in equine urine. The modification to the method was simple to make and quick to setup and optimize. The use of backflushing technology was found to offer significant benefits in terms of sample throughput and improved system robustness.     

Quality assurance in clinical chemistry laboratories in the UK

 Since the mid-1960s quality assurance in clinical chemistry has progressed from a need to define and improve precision and accuracy in analytical test procedures to an all-embracing process of assuring that the whole process of pre-analytical, analytical and post-analytical phases of handling patient samples is managed effectively and efficiently. Automated and computer-controlled equipment has reduced many of the analytical errors, in particular in imprecision, that were present in manual analysis. New management techniques have been developed to control the quality and appropriateness of results. Developments in internal quality control and external quality assessment procedures have enabled laboratories to continually improve the quality of assays. Laboratory accreditation and external quality assessment scheme accreditation have ensured that peer review and peer pressure have been applied to both laboratory and external quality assessment scheme performance. As the NHS reviews its priorities and places more emphasis on primary care provider demands, hospital laboratories will of necessity assist with near patient testing outside the laboratory. This will provide new challenges to the quality of the service provided. Received: 2 July 1998 · Accepted: 1 August 1998     

A routine method for the analysis of mononitro-PAH in immission and emission samples

Summary A routine method for the identification and quantification of mononitrated polycyclic aromatic hydrocarbons in environmental samples has been developed. Micro-scale liquid-liquid partition between dimethylformamide and cyclohexane and HPLC on normal-phase silica gel columns are used for clean-up of samples. This preconcentration scheme is time-saving and uses a minimal amount of solvents. Identification and quantification are performed by GC/ECD and GC/MS in the selected ion monitoring mode. The analytical scheme has been optimized under use of standard substances by variation of several parameters in different steps of the analysis. The method was applied to the NBS Reference Material SRM 1649 Urban Dust, to urban air samples from the city of Vienna as well as to combustion emissions.

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Eine Routinemethode zur Immissions- und Emissionsmessung von Mononitro-PAH

Zusammenfassung Es wurde eine Routinemethode zur Identifizierung und Quantifizierung von mononitrierten polycyclischen aromatischen Kohlenwasserstoffen in Umweltproben entwickelt. Zur Vortrennung der Proben wurde eine Flüssig-flüssig-Verteilung im Mikromaßstab zwischen Dimethylformamid und Cyclohexan und eine HPLC-Auftrennung an Silicagel-Säulen angewandt. Diese Aufarbeitungsmethode erwies sich gleichzeitig als zeit- und lösungsmittelsparend. Die Identifizierung und Quantifizierung der Nitro-PAHs erfolgt mittels GC/ECD und GC/MS im selected ion monitoring-Modus. Der Analysenvorgang wurde unter Verwendung von Standardsubstanzen durch Änderung der verschiedensten Parameter in den einzelnen Analysenschritten optimiert. Praktisch angewandt wurde die vorliegende Methode schließlich zur Untersuchung von Proben des Standardstaubs NBS Standard Reference Material SRM 1649 Urban Dust, von Stadtluft an einer verkehrsreichen Kreuzung in Wien und von Emissionen verschiedener Holzverbrennungsanlagen.

     

Determination of phytohormones in plant samples based on the precolumn fluorescent derivatization with 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene by HPLC for routine use

Six phytohormones including indole butyric acid (IBA), naphthalene acetic acid (NAA), 2,4-dichloro-phenoxy acetic acid (2,4-D), indole-3-acetic acid (IAA), abscisic acid (ABA), and salicylic acid (SA) in crude plant extractions have been quantitated by means of high-performance liquid chromatography (HPLC) with fluorescence detection based on the precolumn derivatization using 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene (BODIPY-aminozide), a fluorescent reagent synthesized in our lab recently. The optimization of derivatization conditions was carefully studied by an L(25) (5(6)) orthogonal array design (OAD) with five factors at five levels that are important influence parameters in the improvement of derivatization efficiency. The separation conditions were also studied in detail. Under the optimal conditions, the detection limits (S/N=3) of the six phytohormones were found from 0.12 to 0.75 nM. The proposed method was the first investigation of aminozide for the analysis of phytohormones and has been successfully applied to the determination of phytohormones in plant samples such as cucumber and tomato with recoveries of 94-105%.