Testing analytical data

A laboratory information management system (LIMS) is a computer or computer network used to automate the acquisition and management of raw analytical data. In its simplest form, it tracks samples and test results through analytical laboratories and provides summaries of the status of these samples and tests. In its most advanced form, the system is interfaced to the laboratory s instmmentation and communication network to allow automation of data gathering, compilation, and reporting. 

Statistical Control. Statistical quahty control (SQC) is the apphcation of statistical techniques to analytical data. Statistical process control (SPC) is the real-time apphcation of statistics to process or equipment performance. Apphed to QC lab instmmentation or methods, SPC can demonstrate the stabihty and precision of the measurement technique. The SQC of lot data can be used to show the stabihty of the production process. Without such evidence of statistical control, the quahty of the lab data is unknown and can result in production challenging adverse test results. Also, without control, measurement bias cannot be determined and the results derived from different labs cannot be compared (27). 

Rothwell and Wain (126) have isolated in crystalline form a growth inhibitor from Lupinus luteus (yellow lupine) pods which they have partially characterized. Analytical data suggested that the inhibitor possessed the characteristics of an unsaturated hydroxyketo acid. Inhibition in the wheat coleoptile cylinder test was obtained with concentrations of 0.25 to 1.0 p.p.m. 

Observations of the test subjects during the course of the field portion of the worker exposure or re-entry study are extremely important in order to interpret the data that are gathered at the field site and to interpret the final analytical data. There are two schools of thought when making observations of field workers during mixer-loader/applicator worker exposure or re-entry studies. 

Fig. 2.19. Various sets of analytical data (A) Hard reference data set, mR(x). (B) Hard test data set, mT(x), which is slightly shifted compared with (A). (C) Fuzzy set of test data, mT(x) = exp (—(x — a)2/b2). (D) Intersection mT R(x) of test data and reference data which is empty in this case. (E) Intersection of fuzzed test data and reference data with a membership value of about 0.8 in this case...

The most common types of analyses are the identification test, the quantitative determination of active ingredients or major component, and the determination of impurities. The identification test provides data on the identity of the compound or compounds present in a sample. A negative result signifies that the concentration of the compound(s) in sample is below the DL of the analyte(s). The quantitative method for the major component provides data of the exact quantity of the major component (or active ingredients) in the sample, and a reported concentration of the major component must be higher than the QL. In a Determination of impurities test, one obtains data regarding the impurity profile of a sample, and can be divided into a limit test or quantitative reporting of impurities (see Table 1, which has been modified from Refs. [1] and [8]). 

Table 34-2 Analytical data entry for comparison of two methods tests...

Provided the sample matrix and analyte concentration are appropriate, matrix Certified Reference Materials (CRMs) can make ideal proficiency testing samples. The assigned value is the certified value given on the certificate accompanying the CRM. The certificate will also give an uncertainty estimate for the certified value, and the use of CRMs allows the traceability of analytical data to be established. However, matrix CRM availability is limited and the materials are often expensive. Hence, Certified Reference Materials are seldom used as PT samples. 

Quantitative information about the first coordination sphere structure depends on analysis of EXAFS data. From analytical data or knowledge of common ligands in metalloenzymes (N, O, S, Se), one can decide which ligands are likely to be present in the coordination sphere. An example discussed by Scott4 tests the hypothesis of a Cu(II)-S bond being present in the compound shown in Figure 3.3. 

FDA routinely requires analytical data on tests under review to demonstrate that they measure what they claim to measure. Analytical performance is usually directed at evaluating a test s accuracy or bias compared with a predicate or reference test, precision or repeatability, and analytical specificity and analytical sensitivity. 

Snow, especially its water-soluble fraction, is one of the most sensitive and informative indicators of mass-transfer in the chain air - soil - drinking water. Therefore analytical data on snow-melt samples were selected for inter-laboratory quality control. Inter-laboratory verification of analytical results estimated in all the groups have shown that relative standard errors for the concentrations of all the determined elements do not exceed (5-15)% in the concentration range 0.01 - 10000 microg/1, which is consistent with the metrological characteristics of the methods employed. All analytical data collected by different groups of analysts were tested for reliability and... 

Karabash. Successive testing of derivative hypotheses showed that hypothesis HI is true for any set of analytical data of all groups involved in the investigation [1]. A linear correlation was established between the concentrations of elements in sets of snow-melt samples when comparing then in the logarithmic scale, equation (1)... 

The analytical data concerning this second period are, at present being processed. At a first, brief examination, however, considerable dif ferences in final characteristics (at the end of the tests), already emer ge, in response to the kind of storage method adopted. 

Thus, when a property of the sample (which exists as a large volume of material) is to be measured, there usually will be differences between the analytical data derived from application of the test methods to a gross lot or gross consignment and the data from the sample lot. This difference (the sampling error) has a frequency distribution with a mean value and a variance. Variance is a statistical term defined as the mean square of errors the square root of the variance is more generally known as the standard deviation or the standard error of sampling. 

Analysts need consistent, reliable, and credible methodologies to produce analytical data about gaseous emissions (Pamaik, 2004). To fulfill this need in this book, this chapter is devoted to descriptions of the various analytical methods that can be applied to identify gaseous emissions from a refinery (ASTM, 2004 IP, 2001). Each gas is, in turn, referenced by its name rather than the generic term petroleum gas (ASTM D4150). However, the composition of each gas varies, and recognition of this is essential before testing protocols are applied. 

Analytical data generated in a testing laboratory are generally used for development, release, stability, or pharmacokinetic studies. Regardless of what the data are required for, the analytical method must be able to provide reliable data. Method validation (Chapter 7) is the demonstration that an analytical procedure is suitable for its intended use. During the validation, data are collected to show that the method meets requirements for accuracy, precision, specificity, detection limit, quantitation limit, linearity, range, and robustness. These characteristics are those recommended by the ICH and will be discussed first. 

RuleMaker, a subsystem of RuleMaster, induces rules for all situations from examples that may cover only some of the cases. At the heart of the induction process is the creation of an induction file, which in part includes examples indicating what the expert system should do under different circumstances. Now, in the example above, THE RULES FOR CORRELATING VARIOUS CHEMICAL AND PHYSICAL PARAMETERS OF THE HAZARDOUS CHEMICALS TESTED WITH THE PROTECTIVE ABILITY OF THE SELECTED GLOVE MATERIALS ARE NOT KNOWN — THEY WILL HAVE TO BE INDUCED FR04 THE ANALYTICAL DATA. 

The precision and accuracy of the overall method was assessed by collecting and analyzing three sets of samples from test atmospheres of known concentration. An overall coefficient of variation of 10% for all analytical data and accuracy of 10% was required for method validation. 

TGA Details of the test method must be provided. Appropriate validation data have been generated for the test method. The limits proposed are based on batch analytical data and are in compliance with official standard and/or relevant accepted guidelines if applicable. Self-assessable changes... 

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