Quality control and assessment

A further distinction is made between pure solutions and matrix-based RMs. The former are available for many organic and inorganic analytes, with certified concentrations, but their role in quality control and assessment is limited. They may be used for the preparation of calibration solutions for a particular measurement but more usually these materials represent the base for traceability, through secondary... 

DSC is increasingly being applied to the study of epoxy resin cure in combination with other analytical methods such as nuclear magnetic resonance and Fourier transform infra-red spectroscopy, chromatographic methods, and dynamic mechanical or dielectric studies. It is probably as part of such combined investigations that DSC can be used most effectively in basic research, and in quality control and assessment. 

Some of the most relevant procedures for the analysis of K-vitamers are brought together in Table 5. It should be clear that again LC is the technique of choice, as this technique is applied both to the sample cleanup and to the analytical measurement of vitamin Ki(20) in different matrices. As with all modern analytical programs, a keystone for success is a sound quality control and assessment strategy, which should always include the exchange of samples between different analytical laboratories and the use of round robin external quality assurance schemes wherever possible. 

The focus of this chapter is on the two principal components of a quality assurance program quality control and quality assessment. In addition, considerable attention is given to the use of control charts for routinely monitoring the quality of analytical data. 

Finally, the textbook concludes with two chapters discussing the design and maintenance of analytical methods, two topics of importance to analytical chemists. Chapter 14 considers the development of an analytical method, including its optimization, verification, and validation. Quality control and quality assessment are discussed in Chapter 15. 

The components of a quality assurance program are designed to serve the two functions just mentioned—control and assessment. Quality control operations are defined by operational procedures, specifications, calibration procedures, and standards and contain the following components ... 

In the production of anionic surfactants, the analytical procedures to be adopted for quality control and/or assessment are of particular importance. Their reliability as well as their time and chemical demand is a fundamental topic for the economy and success of the surfactant production cycle. To this end the most important analyses to be done on the various types of anionic surfactants are outlined in Tables 15-19. Mention must be made of potentiometric titration of the sulfonic acid (whatever the processed feedstock), which allows one to obtain reliable results over a very short time. 

It must be remarked that terminology is not consistent and there are many widely used synon)ms. Quality control in this Chapter refers to practices best described as internal quality control. Quahty assessment is often referred to as external quality control, proficiency testing, interlaboratory comparisons, round robins or other terms. Internal Quality Control and External Quality Assessment are preferred because they best describe the objectives for which the RMs are being used, i.e. the immediate and active control of the results being reported from an analytical run or event, and an objective, retrospective assessment of the quality of those results. 

Certificatioii and availability of reference materials are dealt with elsewhere in this book but in keeping with the title it is appropriate to discuss the proper usage of RMs for quality control and quality assessment. 

The primary purposes for which reference materials are employed are encompassed within the laboratory Quality Assurance Procedures. Quality assurance comprises a number of management responsibilities which focus on how the laboratory is organized, how it deals with situations, how it interacts with users, together with analytical responsibilities re internal quality control and external quality assessment (Sargent 1995 Burnett 1996). Ideally each component follows a documented protocol and written records of all activities are maintained. 

Quality control describes the measures used to ensure the quality of individual results or a batch of results. The measures used will vary according to the particular application. It is a means of evaluating the current performance of the method being used and the general procedures used in the laboratory. There are two types of quality control, namely internal quality control and external quality assessment. These are covered in detail in Chapters 6 and 7, respectively. 

Several algorithms are available for the analysis of MS/MS spectra including SEQUEST, MASCOT, and X Tandem among others. Note that additional secondary quality control of assessment of MS/MS data has recently been implemented to assess identification probabilities and false positivity rates. The MS/MS spectra from an experiment can be interrogated against a concatenated forward and reverse database and an assessment of the intrinsic error rate of the data set can be made. Other approaches for secondary analysis of matching scores for peptide sequencing data include XCorr score normalization routines that are independent of peptide and database size.33... 

Ocean Data Evaluation System (ODES) Data Submissions Manual QA/QC Guidance for Sampling and Analysis of Sediments Water and Tissue for Dredged Material Evaluations Chemical Evaluations Quality Assurance Plan for the National Pesticide Survey of Drinking Water Wells Analytical Method 2, Chlorinated Pesticides Quality Assurance Project Plan for Analytical Control and Assessment Activities in the National Study of Chemical Residues in Lake Fish Tissue... 

In the past, laboratories have justified the initial investment in dedicated automation on the basis of the large number of identical, repetitive operations carried out. Fixed or dedicated automation is utihzed for large quantities of standard procedures, such as those found in manufacturing environments or in clinical laboratories. Fixed automation follows a predetermined sequence of steps to perform a defined procedure although efficient, it can only perform one repetitive procedure. Robotics, however, can provide flexible automation to meet the changing needs typical of quality control and research laboratories. Flexible automation is programmed by individual users to perform multiple procedures, and can be quickly reprogrammed to accommodate new or revised procedures. In these situations, a careful assessment of the software overhead must be made before a decision to purchase is made. 

E1N SIGHT, and others. All of these programs are specifically directed toward the multivariate analysis of analytical chemical data both in assessing data quality (quality control and quality assurance) and in interpreting data to provide insight into the complex system under investigation. 

External Quality Control and Accreditation Participation in PT schemes is an objective means of evaluating the reliability of the data produced by a laboratory. Another form of external assessment of the laboratory performance is the physical inspection of the laboratory to ensure that it complies with externally imposed standards. Accreditation of the laboratory indicates that it is applying the required... 

Two elements of quality assurance are quality control and quality assessment. Quality control is a set of measures implemented within an analytical procedure to assure that the process is in control. A combination of these measures constitutes the laboratory QC program. A properly designed and executed QC program will result in a measurement system operating in a state of statistical control, which means that errors have been reduced to acceptable levels. An effective QC program includes the following elements ... 

Regulatory Affairs The FDA s Office of Regulatory Affairs is increasingly active in international standards activities relevant to quality control and conforming assessment, including activities relevant to ISO—9001 and laboratory regulation. 

Quality assurance (QA) has been described as a system of activities that assures the producer or user of a product that defined standards of quality with a stated level of confidence are met. Quality control (QC) differs in that it is an overall system of activities that controls the quality of a product so that it meets the needs of the users (Taylor, 1987). In other words, QC consists of the technical activities to control and assess the quality of the measurements, while QA is the management system that ensures that an effective QC system is working as planned. 

Ketterer, M.E. (1992) Assessment of overall accuracy of lead isotope ratios determined by inductively coupled plasma mass spectrometry using batch quality control and the Youden two-sample method. J. Anal. Atomic Spectrom. 7, 1125-1129. 

With strict quality control and careful product analysis, the incidence of such deleterious reactions can be minimized. Reaction conditions and ingredient selection bear importantly on the character of the final product, and it must be emphasized that adding even a single new component to the mixture raises the possibility of new reactions whose effect on the food s nutritive value and safety must be assessed. 

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