Collection analysis matrix quality assurance

The paper reviews the subject literature concerning analytical procedures routinely sed for monitoring polybrominated diphenyl ethers (PBDE) in environmental samples. It describes and summarizes subsequent stages of analytical procedure including sample collection and preparation, extraction, clean-up and final determination. Different approaches with their advantages and limitations are presented. Special attention is drawn to the newly developed, promising extraction techniques, especially: liquid-liquid-microextraction (LLME) with its modifications, cloud point extraction (CPE) and hollow fiber microextraction...

Management of Tata Steel, the largest steel making company of India in the private sector, felt the need to develop a framework to determine the levels of ergonomic performance at its different workplaces. The objectives of the study are manifold: to identify and characterize the ergonomic variables for a given worksystem with regard to work efficiency, operator safety, and working conditions, to design a comprehensive Ergonomic Performance Indicator (EPI) for quantitative determination of the ergonomic status and maturity of a given worksystem...

The development of a systematic approach which can be used as a decision-making tool to extend or shorten the post-closure care (PCC) period requires technically sound and justifiable methods. These methods can incorporate analysis and interpretation of available data and information from closed landfill. Analysis of existing data from closed landfills may present challenges due to variations in the data collection procedures, data analysis methods and reporting methodologies used during active and post-closure periods of a landfill...

OBJECTIVES: To evaluate the effectiveness of hearing conservation programs (HCP) and their specific components in reducing noise-induced hearing loss (NIHL). METHODS: This retrospective cohort study was conducted at one food-processing plant and two automotive plants. Audiometric and work-history databases were combined with historical noise monitoring data to develop a time-dependent exposure matrix for each plant. Historical changes in production and HCP implementation were collected from company records, employee interviews and focus groups...

When evaluating candidate prophylactic HIV and cancer vaccines, intracellular cytokine staining (ICS) assays that measure the frequency and magnitude of antigen-specific T-cell subsets are one tool to monitor immunogen performance and make product advancement decisions. To assess the inter-laboratory assay variation among multiple laboratories testing vaccine candidates, the NIH/NIAID/DAIDS in collaboration with BD Biosciences implemented an ICS Quality Assurance Program (QAP). Seven rounds of testing have been conducted in which 16 laboratories worldwide participated...

Dual distribution systems are becoming increasingly common in greenfield housing developments in Australia for the redistribution of recycled water to households for non-potable use. Within such schemes there exists the potential for cross-connections between recycled and drinking water systems. Due to the high level of recycled water treatment, these events are unlikely to lead to outbreaks of illness in the community. Nonetheless, they do represent a breach of the recycled water risk management strategy and therefore an elevated level of risk to consumers...

Unlike quantitative analysis, which must commonly undergo an extensive method validation process in labs to assure quality of results, the quality of the qualitative results in the analysis of pesticide residues in food is generally ignored in practice. Instead, chemists tend to rely on advanced MS techniques and general subjective guidelines or fixed acceptability criteria when making analyte identifications. All analytes and matrices have unique characteristics that make this current approach less effective than desirable in many real-world situations...

An understanding of the principles of degradation, as well as the statistical tools for measuring product stability, is essential to management of product quality. Key to this is management of vaccine potency. Vaccine shelf life is best managed through determination of a minimum potency release requirement, which helps assure adequate potency throughout expiry. Use of statistical tools such a least squares regression analysis should be employed to model potency decay. The use of such tools provides incentive to properly design vaccine stability studies, while holding stability measurements to specification presents a disincentive for collecting valuable data...

Multi-wavelength fingerprints of Cassia seed, a traditional Chinese medicine (TCM), were collected by high-performance liquid chromatography (HPLC) at two wavelengths with the use of diode array detection. The two data sets of chromatograms were combined by the data fusion-based method. This data set of fingerprints was compared separately with the two data sets collected at each of the two wavelengths. It was demonstrated with the use of principal component analysis (PCA), that multi-wavelength fingerprints provided a much improved representation of the differences in the samples...

Soil samples collected from an electronic waste recycling site were prepared by using Soxhlet extraction and multiple-step column chromatographic clean-up. Gas chromatography/ion trap mass spectrometry method was developed to determine polybrominated diphenyl ethers (PBDEs) in the sample extracts. The method performance was evaluated by the recovery of (13)C-labeled internal standards and by analyzing quality assurance and quality control samples. Relative error and relative standard deviation obtained from the analysis of duplicated samples and spiked matrix were better than 10%...

External quality assessment surveys for thyroid-related antibodies have been offered by INSTAND for 20 years. During this time, some problems have remained, especially those between the similarity of samples sent and routine patient samples. Here the questions of "matrix effects" and "commutability of results" are topics discussed at most EQA-meetings. This short communication deals with the effects of lyophilization on results for thyroid-associated antibodies in an EQA-survey carried out by over 230 participants in October 2005 by INSTAND in Düsseldorf, Germany...

There is a substantial list of pre-analytical variables that can alter the analysis of blood-derived samples. We have undertaken studies on some of these issues including choice of sample type, stability during storage, use of protease inhibitors, and clinical standardization. As there is a wide range of sample variables and a broad spectrum of analytical techniques in the HUPO PPP effort, it is not possible to define a single list of pre-analytical standards for samples or their processing. We present here a compendium of observations, drawing on actual results and sound clinical theories and practices...

An in-house reference soil sample containing high levels of naturally occurring radioactive materials collected from contaminated areas in the Syrian oilfields has been prepared as a part of the quality assurance program in AECS. Homogeneity of the sample has been examined using three methods, viz. particle size distribution of the sample matrix, total alpha/beta counting and gamma spectrometry. In conjunction with Dixon and Grubb tests as statistical tools, ten random samples from the original sample were used for this investigation...

Serum proteomic pattern diagnostics is an emerging paradigm employing low-resolution mass spectrometry (MS) to generate a set of biomarker classifiers. In the present study, we utilized a well-controlled ovarian cancer serum study set to compare the sensitivity and specificity of serum proteomic diagnostic patterns acquired using a high-resolution versus a low-resolution MS platform. In blinded testing sets, the high-resolution mass spectral data contained multiple diagnostic signatures that were superior to the low-resolution spectra in terms of sensitivity and specificity (P<0...

Workplace dermal exposure assessment is a complex task that aims to understand the dynamic interaction between the skin and the hazardous substances present in the surrounding environment. A European project known as RISKOFDERM gathered dermal exposure data in 85 workplaces (industrial and other types) in five countries in Europe. In order to optimize data collection and to develop a representative picture of dermal exposure, scenarios (tasks made up of a series of activities) were grouped together into dermal exposure operation units (DEOs)...

Haemovigilance has become a crucial part of the blood safety concept. In the Member States of the European Union, national haemovigilance systems are already in place or are developing. With the coming into force of the European Blood Directive 2002/98/EC, Community haemovigilance has become a priority: cooperation between the national haemovigilance systems will be of vital interest. The process of collaboration has already been initiated some years ago by the European Haemovigilance Network (EHN) with the following objectives: to favour the exchange of valid information between its members, to increase rapid alert/early warning between the members, to encourage joint activities between the members and to undertake educational activities relating to haemovigilance...

BACKGROUND: Chemical speciation analysis is essential for the biological monitoring of inorganic arsenic exposure using urine as indicator medium. There is increasing demand for a certified reference material (CRM) of urine matrix for arsenic speciation. METHODS: Urine (10 L) was collected from non-occupationally exposed Japanese males. We prepared 954 bottles of urine, each containing approximately 10 mL, after filtering and blending the urine stock. The urine in each bottle was freeze-dried...

We found evidence of bias due to matrix effect in 70% of 37 instrument/reagent-specific systems analyzing the total cholesterol content of a lyophilized proficiency testing material. We used a computational method to remove bias due to matrix effect from the proficiency testing database. After correction for matrix effect bias and when compared with the reference method, 92% to 93% of results for three lyophilized proficiency testing samples analyzed in 1989 and 1990 met the 1992 National Cholesterol Education Program total error goal of 8...

The objective of this collaborative study with the Department of Veterans Affairs (VA), College of American Pathologists (CAP), and the Centers for Disease Control and Prevention (CDC) was to quantitate the matrix-induced biases of cholesterol measurements on the CAP Comprehensive Chemistry Surveys materials used in proficiency testing (PT). A total of 174 VA Medical Centers outpatient clinics and clinical laboratories participate in the VA-CDC National Cholesterol Standardization and Certification Program...

OBJECTIVE: To evaluate the suitability of various commercial preparations for use by the College of American Pathologists as survey materials in assessing high-density lipoprotein cholesterol measurement performance. DESIGN: Lyophilized human serum preparations from six vendors (vendors A through F) were evaluated to determine which material(s) best mimicked the commutability of fresh human serum. Two freshly collected unfrozen pools prepared from donor specimens were analyzed concurrently with the vendor materials to identify sources of variation and possible matrix bias...