Performance evaluation samples

All the analytical data are from the same laboratory consequently, interlaboratory analytical variation is not a factor. The intralaboratory variation for that laboratory was 9.1 percent (i.e., the relative standard deviation based on repetitive analyses of performance evaluation samples). 

One trip blank (Two 40m vials filled with distilled/deionized water) per cooler of volatile organic samples. Performance evaluation sample (optional)... 

Performance evaluation samples. Detection limit should be determined. 

This method is ideally used by analysts experienced in the use of ICP techniques, the interpretation of spectral and matrix interference, and procedures for their correction. It is preferable to demonstrate analyst proficiency through analysis of performance evaluation samples (e.g. reference or certified reference materials) before the generation of routine analysis data. Use of ICP-MS method should be restricted to competent analysts who are knowledgeable in the recognition and in the correction of spectral, chemical and physical interferences. 

The actual mass chromatograms and spectra are received seven days later at which time they are also reviewed. Any discrepancies between the two sets of data are immediately rectified. Data are qualified based on adherence to the method criteria plus the results of the field blank, fortified sample, and performance evaluation sample. Data are qualified as either valid or invalid for remedial site work. 

Certain laboratories can, after a contract has been awarded, register under the Contract Laboratory Program (CLP) of the EPA. To earn a contract, one or more specifically prepared samples must be analyzed under very similar conditions to those used in standard protocols. Only if the data are deemed satisfactory will a contract be awarded. Further evaluation samples must be analyzed at three-month intervals afterward to ensure that performance is being maintained. 

Gas chromatography is especially useful for gas-phase analysis of partial oxidation, hydrogenation, or hydroconversion products as in many cases a full carbon balance (educts, products, and all side products), in order to evaluate sample performance. As the detection and quantification of permanent gases such as N2, 02, CO, and C02 and also of higher boiling compounds are standard separation problems for gas chromatography, it is wise to employ the method regarding this problem. 

Qass A SIMCA Model Validation—Values (Model and Sample Diagnostic) The most direct procedure for performance evaluation of the SIMCA models is to examine how well the models classified the samrics fn m. riJ of... 

Interlaboratory Quality Control. In addition to the mandatory quality control practices just outlined, the laboratory is encouraged to participate in interlaboratory programs such as relevant performance evaluation (PE) studies, analysis of standard reference materials, and split sample analyses. Participation in interlaboratory analytical method validation studies is also encouraged. 

Concentration and Recovery of Solutes. The RO method was evaluated by using small-scale concentrations and selected model organic solutes. Similar concentrations were performed by other researchers by using alternate sampling methods as part of a comparison study. The concentration provided a 50-fold volume reduction (500 L down to 10 L). Field applications of the RO method usually involve sample volumes of 2000-8000 L. No steps were taken to condition membranes and equipment prior to the laboratory tests. This laboratory performance evaluation was conducted, in many respects, as a worst case exercise. 

In the last entry in Table III more than 50 samples were extracted in an experiment surveying the performance of laboratory robotic equipment. These included 2.0 gram samples of soils extracted with pure C02,2.5 gram samples of a reverse phase material extracted with C02 and mixtures of C02 with various modifiers, 2.0 gram samples of ground coffee plus aliquots of modifiers dispersed on the samples within the sample thimble extracted with pure CO and 20 microliter aliquots of performance evaluation standard (PES, octadecane in isooctane) on simple matrices extracted with pure C02. The variety of analytes and complex matrices along with the number of different runs clearly show that the instrumentation is reliable. 

Figure 4. Chromatographic analysis of extracted fractions produced by extracting a "check-out" sample, the Performance Evaluation Standard, for the HP7680A SFE on two occasions one year apart.

On the first stage of hydrogenation reaction the C/H composition of fulleranes can be approximately determined by XRD from increase of unit cell parameter. The crystal structure of fulleranes powder remains to be fee like in pristine C60 but the cell parameter increases proportionally to the number of attached hydrogen atoms due to increase of van der Waals diameter of molecules. Using chemical analysis on carbon/hydrogen ratio performed on samples hydrogenated at various conditions we constructed the dependence which could be used for approximate evaluation of hydrogen content from known cell parameter determined from powder XRD, see Fig. 5.3... 

Van Der Veen and Alink [7] have reviewed methods for evaluating the performance of sampling, sample preparation and subsampling. Several new methods and apparatus for sampling solid matrices have been described recently [5-12] and, in particular, a new sampling method has been developed that is especially adapted to the specific conditions of sampling contaminated bulk soil masses [8]. 

Accuracy will be evaluated by performing a sample analysis on three lots of substance J tablets. Each lot of substance J tablets will be prepared in triplicate and analyzed as per the method. The assay results will be compared to those obtained from the corporate QC laboratory. 

Patterson DG Jr, Turner WE, Isaacs SG, et al. 1990. A method performance evaluation and lessons learned after analyzing more than 5,000 human adipose tissue, serum, and breast milk samples for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Chemosphere 20 829-863. 

The necessary components of a complete QA/QC program include internal QC criteria that demonstrate acceptable levels of performance, as determined by a QA review (audit). External review of data and procedures is accomplished by the monitoring activities of accreditation organizations such as the Standards Council of Canada (SCC, 2005). This includes laboratory evaluation samples (PT samples, see above) and a periodic (sometimes every 2 years) on-site assessment of all QA/ QC procedures, performed by external assessors from the accrediting organization. 

An alternative method for performance evaluation is to participate in inter-laboratory comparisons, often known as round-robins . Usually this involves sending sub-samples of a selection of appropriate samples to a number of independent laboratories, to be analysed either by a fully specified procedure and technique, or to be analysed by whatever method each laboratory choses. Obviously, these two approaches test different things. The former indicates the precision attainable using a specified procedure, and tests both the adequacy of the specification and the competence of participating laboratories. Only the... 

The training material developed by the TrainMiC board was compiled as the EUR report 20841 and is available for download from the TrainMiC web site [96]. At present seven modules are bnalized A general introduction to Metrology in Chemistry Validation of measurement procedures Traceability of measurement results Uncertainty of measurement results Proper use of certi bed reference materials (CRM) Interlaboratory comparisons (ILC), and Applied statistics, relevant for the calculation of an uncertainty budget or the performance evaluation. Additional modules are in progress to cover issues such as sampling, QC, and QA. 

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