Laboratory important qualities

Using these rhelogical methods laboratories for quality control and research and development have good tools to characterize pectins in gels and solutions. The most important points are the reproducable handling, pretreatment, and measurement of the samples and the knowledge which information can be derived from the measured data regarding the texture, the production parameters, and the sensory evaluation of the product. 

E. The degree of occlusion (in fact, the tightness of the wrap over the test site) also alters percutaneous absorption and therefore irritation. One important quality control issue in the laboratory is achieving a reproducible degree of occlusion in dermal wrappings. 

Analytical laboratories, especially quality assurance laboratories, will often maintain graphical records of statistical control so that scientists and technicians can note the history of the device, procedure, process, or method at a glance. The graphical record is called a control chart and is maintained on a regular basis, such as daily. It is a graph of the numerical value on the y-axis vs. the date on the x-axis. The chart is characterized by five horizontal lines designating the five numerical values that are important for statistical control. One is the value that is 3 standard deviations from the most desirable value on the positive side. Another is the value that is 3 standard deviations from the most desirable value on the negative side. These represent those values that are expected to occur only less than 0.3% of the time. These two numerical values are called the action limits because one point outside these limits is cause for action to be taken. 

In the food industry it has often been difficult to obtain true viscosity measurements (unithj.j) of complex fluid foods such as coarse fruit suspensions. These are usually non-Newtonian suspensions. Fruit concentrates are dispersions of solid particles (pulp) in aqueous media (serum). Their rheological properties are of interest in practical applications related to processing, storage stability, and sensory properties. Expensive rheometers are often not available in quality control and product development laboratories. However, viscosity is nonetheless an important quality factor of these products. 

The ISO/IEC GUIDE 25 [1] stresses, in paragraphs 5.6 and 9.3, the importance of participation in proficiency testing programs or other interlaboratory comparisons, as appropriate and when suitable programs are available. This would imply that such activities are an important part of a laboratory s quality control procedures. 

When the analytical laboratory is not responsible for sampling, the quality management system often does not even take these weak links in the analytical process into account. Furthermore, if sample preparation (extraction, cleanup, etc.) has not been carried out carefully, even the most advanced, quality-controlled analytical instruments and sophisticated computer techniques cannot prevent the results of the analysis from being called into question. Finally, unless the interpretation and evaluation of results are underpinned by solid statistical data, the significance of these results is unclear, which in turn greatly undermines their merit. We therefore believe that quality control and quality assurance should involve all the steps of chemical analysis as an integral process, of which the validation of the analytical methods is merely one step, albeit an important one. In laboratory practice, quality criteria should address the rationality of the sampling plan, validation of methods, instruments and laboratory procedures, the reliability of identifications, the accuracy and precision of measured concentrations, and the comparability of laboratory results with relevant information produced earlier or elsewhere. 

True event. A Marketing executive was touring R D laboratories and asked a key synthetic chemist working on antibacterials what she thought was the most important quality in an antibiotic after therapeutic activity. She replied, lack of bacterial resistance. When the executive emphasized that Marketing was most concerned about lack of side effects, the scientist said, No one ever told me that. ... 

Nowadays it is generally accepted that laboratory proficiency testing schemes are an important quality assurance tool in environmental monitoring programmes. Apart from using validated analytical methods and internal laboratory quality control procedures, the regular participation of laboratories in interlaboratory comparisons is required to ensure the accuracy and comparability of data. 

Discretion is advised when comparing the performance of high temperature adhesives where the evaluations were performed in different laboratories. Important parameters critical to the performance of the adhesive, such as quality of the polymer, adhesive type, adherend, surface treatment, bonding conditions, aging and test conditions, often vary between one investigation and another. 

Quality control data were obtained at the field laboratory and input daily to a database which incorporated validation of data values, and routine plotting and statistical analysis of important parameters. The database is easily accessible to persons in various company locations. Table 7 shows statistics compiled on the quality control acceptance tests, with a comparison of the data obtained in the field lab and that supplied by the polymer manufacturer. It shows that all the important quality control parameters were held to reasonable tolerances during the project. Both the standard deviations of the values and the agreement between the vendor s lab and the field lab are considered excellent. 

In any laboratory where quality assurance is important, the performance of aU instruments, including FT-IR spectrometers, should be tested on a regular basis. Measuring the rms noise on the 100% line between, say, 4000 and 3800 cm and 2200 and 2000 cm at least once a week gives users a good indication as to whether the performance of their instrument is still acceptable. The American Society for Testing and Materials (ASTM) has approved an additional series of... 

The traditional approach for process monitoring is to compare measurements against specified limits. This limit checking technique is a standard feature of computer control systems and is widely used to validate measurements of process variables such as flow rate, temperature, pressure, and liquid level. Process variables are measured quite frequently with sampling periods that typically are much smaller than the process setthng time (see Chapter 17). However, for most industrial plants, many important quality variables cannot be measured on-line. Instead, samples of the product are taken on an infrequent basis (e.g., hourly or daily) and sent to the quality control laboratory for analysis. Due to the infrequent measurements, standard feedback control methods fike PID control cannot be applied. Consequently, statistical process control techniques are implemented to ensure that the product quality meets the specifications. 

Quality in NDT depends upon a number of factors. Qualification of NDT personnel, technical state and correctness of choice of testing equipment, availability of approved working procedures of examination, calibration of NDT equipment have decisive importance among those factors of an NDT laboratory. Assessment of NDT laboratory competence is provided through accreditation in compliance with the EN 45000 series standards. 

An important step in developing a standard method is to determine which factors have a pronounced effect on the quality of the analytical method s result. The procedure can then be written to specify the degree to which these factors must be controlled. A procedure that, when carefully followed, produces high-quality results in different laboratories is considered rugged. The method by which the critical factors are discovered is called ruggedness testing. ... 

Internal methods of quality assessment should always be viewed with some level of skepticism because of the potential for bias in their execution and interpretation. For this reason, external methods of quality assessment also play an important role in quality assurance programs. One external method of quality assessment is the certification of a laboratory by a sponsoring agency. Certification is based on the successful analysis of a set of proficiency standards prepared by the sponsoring agency. For example, laboratories involved in environmental analyses may be required to analyze standard samples prepared by the Environmental Protection... 

Quality control encompasses all activities used to bring a system into statistical control. The most important facet of quality control is written documentation, including statements of good laboratory practices, good measurement practices, standard operating procedures, and protocols for a specific purpose. 

Quality Control Records. Accurate quality control records are of utmost importance and may be required by law, as in the pharmaceutical industry. A few years ago, mandatory Good Manufacturing Practices were proposed for the cosmetic industry. Although the proposal was later dropped, many manufacturers go by the rules worked out at that time for laboratory testing and record keeping. The food industry also requires extensive testing and record keeping. 

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