Accuracy evaluation reproducibility

When one is deciding what column geometry is optimal for trace analysis with unlimited sample volume, two additional points should be evaluated. First, to what extent does the analysis require accurate and reproducible injections Strict performance specifications may eliminate microbore columns from consideration. The accuracy and reproducibility of injection systems that deliver 0.1-, 0.2-, and 0.5-/xL samples have not been adequately characterized. Second, if the analyte of interest requires postcolumn derivatization, construction of a postcolumn reaction system that is compatible with the exceedingly small band volumes characteristic of microbore columns may be extremely difficult, but not impossible. Apffel et al. (28) developed and evaluated both packed-bed and open tubular postcolumn reactors for use with 1-mm i.d. analytical columns. Catecholamines were postcolumn derivatized with o-phthal-aldehyde and detected spectrofluorometrically. The 5-/zm particle... 

When conducting an inspection, several target areas must be evaluated. Control limits or "charts" are helpful and should be established by plotting the defined limits of acceptable quality control. These charts are important tools for assessing laboratory precision, accuracy, and reproducibility. They can be based on a curve established from the high, mid, and low concentrations of a standard analyte. Either the mid level or the average of the three concentrations then becomes the mid-line for the control chart. Acceptable levels of fluctuation for routine mid-level standards,... 

We have evaluated three different techniques to generate QSAR models, namely Comparative Molecular Field Analysis (CoMFA), Comprehensive Descriptors for Structural and Statistical Analysis (CODESSA), and Hologram QSAR (HQSAR). More specifically they were evaluated for their utility (predictivity, speed, accuracy, and reproducibility) to predict ER binding activity quantitatively (Tong et al., 1998 Shi et al., 2001). Common to the three QSAR methods is the... 

Di Palma S, Collins N, Bilous M, Sapino A, Mottolese M, KapranosN.etal. A quality assurance exercise to evaluate the accuracy and reproducibility of chromogenic in situ hybridisation for HER2 analysis in breast cancer. J Clin Pathol 2008 61(6) 757-60. 

Bingham D, Kendall J, Clancy M. The portable laboratory an evaluation of the accuracy and reproducibility of I-STAT. Ann Clin Biochem 1999 36 66-71. 

FdPLC has contributed many successes in product development and in quality control for the pharmaceutical industry. The UV detector coupling with HPLC equipment is the most important analytical instrument for preformulation, QC/QA, and in-process control in pharmaceutical analysis. HPLC is a basic and reliable analytical tool for preformulation study because of the high-resolution capacity, accuracy, and reproducibility of the equipment. Its primary function includes search for and detection of impurities in drug substances, as well as stability evaluation of dosage forms in terms of detection and quantitation of degradation products. 

Press ME, Sauter G, Bernstein L, et al. Diagnostic evaluation of HER-2 as a molecular target An assessment of accuracy and reproducibility of laboratory testing in large, prospective, randomized clinical trials. Clin Cancer Res. 2005 11 6598-6607. 

Precision and accuracy With method established perform three runs Perform at least six runs Apply appropriate statistics Evaluate reproducibility of incurred samples in each toxicology species Clearly defined and acceptable Evaluate reproducibility of incurred samples in key studies... 

In the present study, we use the ASCF approach with Hartree-Fock and a wide variety of pure and hybrid density functional approaches to study CEBEs in glycine, methane, ammonia, and water. Each approach is evaluated for its accuracy in reproducing experimental values for the absolute CEBEs in all four molecules, as well as for the intramolecular and intermolecular chemical shifts between like nuclei in the same or different molecules. Several promising candidates are found that can be recommended for future testing to establish accurate and efficient methods for calculations of CEBEs and their chemical shifts in large biomolecules. 

Fig. 11.1 The KT-1000 arthrometer has been widely used for diagnosis and preoperative and postoperative evaluation of ACL-deficient knees, because of its accuracy and reproducibility in the measurements of tibial anterior/posterior translation...

The next section deals with method validation of quantitative TLC methods. Two questions should, however, be answered prior to discussing the validation experiments namely, whether the statistical evaluation of data elements, such as precision, accuracy, and reproducibility should be calculated on the basis of measured peak heights or peak areas, and whether the internal or external standard methods, or area normalization should be used to yield quantitative results for the assay. Without going into detail, the most important advantages and limitations of peak height and peak area measurements, and those of the different methods of quantification are summarized in Table 4. 

Forty-seven peaks representing single or multiple components are obtained from this analysis. A single rather than dual FID is used to increase the accuracy and repeatabihty of this analysis at the expense of doubling the analysis time. The inherent repeatability, accuracy, and reproducibility of this multicolumn technique was evaluated by Van Arkel et al. (92). 

There are many particle-sizing methods as summarized in Table 21.4. Each method has advantages and disadvantages. The method of choice depends on the specific type of powder or dispersion sample to be characterized. The main criteria for evaluating the quality of the particle size results are accuracy, precision, reproducibility, and speed of analysis. 

Currently, nutrient analytical methods development often utilizes the method of standard additions as an intrinsic aspect of the development process. Essentially, the analyte to be measured exists in the matrix to which an identical known pure standard is added. The spiked and non-spiked matrix is extracted and analysed for the nutrient of interest. By spiking at increasing levels the researcher can establish, to some degree of certainty, the recovery and linearity of the standard additions. One can also evaluate data to determine reproducibility, precision, and accuracy. Unfortunately, the method of standard additions does not allow the evaluation of the method at nutrient concentrations less than 100 % of the endogenous level. 

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