Accuracy validation

Butler, W.H., and Nesbet, R.K., 1990, Validity, accuracy, and efficiency of multiple-scattering theory for space-filling scatterers, Phys. Rev. B 42 1518. 

For regulatory purposes, food-based RMs play an important role in validating accuracy of analytical data from use of routine methodology. For example, the quality of data obtained by analytical measurements serves an important function with regard to ensuring nutritional label claims. Unfortunately, and historically in some cases, assay data for the same analyte can vary greatly from laboratory to laboratory. Evalua-... 

Also, according to these regulations [21 CFR 211.194(a)(2)], users of analytical methods described in the USP and the NF are not required to validate accuracy and reliability of these methods, but merely verify their suitability under actual conditions of use... ... 

The first summation Incorporates a block data set for observed monomeric standards the second is a null buffer the third are polymeric standards. Testing through the addition of monomers to polymer standards verified that the decomposition concept is again valid. Accuracy within the chromatogram is the error-determining step. Table I presents analysis of material after blending known quantities. 

Stability testing Results for each pack, methodology, validated (accuracy and precision recorded) Related compounds and decomposition sensitivity, accelerated and real-time data, accelerated 40 °C and 75% RH for six months, real time 30 °C and 70% RH ... 

Other procedural details such as test lot preparation to aliquot all the samples needed for the validation experiments should also be described briefly in this section of the protocol.] Referring to SOP 123, the reportable value is defined as the average of the three replicates. For this validation, accuracy, precision, and linearity of the replicate values will be assessed consequently, the precision of the results reported is at the replicate level not the reportable value level. [Note this practice is done for two reasons first, to conserve resources, and second, when it is not possible to repeat an additional assay with exactly the same sample preparation. The repeatability component of the precision is defined as within-assay variance. Using the replicate values yields a within-assay variance.]... 

Method validation Accuracy three levels in triplicate (70,100, and 130% of... 

FIGURE 6.7 Total error (TE) and precision of validation samples. Data from inter day method validation accuracy and precision runs. The standards were in buffer. Five levels of VS were prepared in buffer and in sample matrix. Open squares TE% in buffer solid squares CV% in buffer open circles TE% in matrix solid circles CV% in matrix. 

Quality Assurance/Quality Control Validation of steps and analytical results throughout, by independent or reference method(s), application of CRMs, RMs, contiol materials (internal QC), interlaboratory comparisons, proficiency tests to validate accuracy and precision competent analyst/specialist... 

Representations of precision (reproducibility) and validity (accuracy). The target for accuracy of a test result is represented by the central disc. For example, this is the correct mean for a sample analyzed by ELISA. Results from five tests are shown as black dots. (A) Data are grouped tightly (reproducible) and all are in the correct result disc (accurate). (B) Although the data are precise (all showing similar results), they all are inaccurate and biased toward the upper left. (C) This shows a wide dispersion of data (not reproducible), but the average result of the data predicts the accurate result confidence in these data is low. (D) This shows both irreproducible results in which the control mean is not reflected by the average of all the results the test is inaccurate... 

Proposed lUPAC nomenclature is scrutinized for validity, accuracy and consistency across all branches of Chemistry, and over Science generally, by lUPAC s Interdivisional Committee on Terminology, Nomenclature and Symbols. The committee has representation from other International Scientific Unions Biochemistry and Molecular Biology (lUBMB), Crystallography (lUCr), Nutritional Sciences (lUNS), Pharmacology (lUPHAR) and Pure and Applied Physics (lUPAP), and from the Bureau International des Poids et Mesures (BIPM) and the International Organization for Standardization (ISO), as well as Divisional and other representatives of lUPAC. 

Most current studies report an internal validation accuracy without an independent validation set. When there are a sufficiently large number of samples, the whole dataset can be split into two, one for training and one for testing (validation) this method is called hold-out validation. When the number of samples is limited, leave-one-out cross validation (LOOCV) is a popular technique. Here, a procedure is repeated N times, and each time a different sample is left out and used for testing the model learned from the remaining (N - 1) samples. The accuracy of... 

Assay for content. The following characteristics are recommended for LC assay validation accuracy, precision, specificity, linearity, and range. The quantitation limit (QL) is assessed for analytes having responses near the QL. Specificity is evaluated as discussed for ID tests. 

For a number of materials it is vital that propaty values are provided which have a validated accuracy and are identified as standard reference data (SRD), preferably with international approval and recognition. The prq>aration of such internationally approved data standards is a timeconsuming and delicate activity that requires a critical evaluation of all the available measurements with a detailed assessment of the accuracy of each individual datum reported. For these reasons, only results obtained in instruments characterized by high quality and a complete working equation based upon a sound theory can be employed for the establishment of standard reference data. Whenever possible the results of measurements made with different experimental techniques should be included. 

Swartz, M. and Krull, I., Analytical method validation Accuracy in quantitation. LC-GC, 23, 46 (2005). 

Klomfar J, Souckova M, Patek J (2010) Surface tension measurements with validated accuracy for four 1-alkyl-3-methylimidazolium based ionic liquids. J Chem Thermodyn 42 323-329... 

Bicego used the similarity-based representation of electronic nose measurements for odor classification with the SVM method.In the similarity-based representation, the raw data from sensors are transformed into pairwise (dis)similarities, i.e., distances between objects in the dataset. The electronic nose is an array of eight carbon black-polymer detectors. The system was tested for the recognition of 2-propanol, acetone, and ethanol, with 34 experiments for each compound. Two series of 102 experiments were performed, the first one with data recorded after 10 minutes of exposure, whereas in the second group of experiments, the data were recorded after 1 second of exposure. The one-versus-one cross-validation accuracy of the first group of experiments was 99% for similarity computed using the Euclidean metric. For the second group of experiments, the accuracy was 79% for the Euclidean metric and 80% for the Manhattan metric. 

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