Quality control points

While quality was formerly achieved by inspection of final products, it is accomplished now by prevention through controlling critical steps in the production processes along the agri-food chain. Hazard analysis critical control points (HACCP) represent a typical example of such a preventive approach. Although this concept was developed primarily to assure food safety, the basic principle is also applicable to assuring non-safety quality attributes such as color, flavor, and nutritional value. " This section translates the HACCP principles into a critical quality control point (CQP) concept that can be part of a system to assure food quality. 

Quality control point source (e.g., 60Co and 137Cs see Fig. 2B.2 for decay schemes)... 

Batch Analyzers. The American Monitor Programachem 1040 does one test at a time on up to 89 samples at up to 15 results per minute. A prepunched program card automatically sets virtually all of the system variables for each method on insertion into the instrument card-reader. A second-generation instrument, the KDA, was shown in 1975. This provides an integrated system from request slip to report form, with a design heavily dependent on the dedicated minicomputer. Another feature offered is graphics, which allows an oscilloscopic display of calibration curves, kinetic reaction-curves, quality-control points, etc. 

Differential scanning ca/orimetry is used for determining the effects of additives and fillers from a process and quality-control point of view. The above graph characterizes LORE foam. 

Although it is a positive QC development that fingerprinting methods have been introduced in the Chinese Pharmacopoeia 2010, at the same time it should be remarked that the techniques and evaluation are still somewhat primitive. Neither of the two proposed methods takes the absolute concentration of constituents into consideration. The specific chromatogram method also does not take the relative concentration into accoimt. From a quality control point of view, it is obvious that differences in absolute as well as relative concentrations influence the quality of a TCM. A good LC fingerprint can provide this information and enables discrimination between samples. Therefore, improved chemometric evaluation protocols are necessary. 

Specifications for gas turbine fuels prescribe test limits that must be met by the refiner who manufactures fuel however, it is customary for fuel users to define quality control limits for fuel at the point of delivery or of custody transfer. These limits must be met by third parties who distribute and handle fuels on or near the airport. Tests on receipt at airport depots include appearance, distfllation, flash point (or vapor pressure), density, freezing point, smoke point, corrosion, existing gum, water reaction, and water separation. Tests on delivery to the aircraft include appearance, particulates, membrane color, free water, and electrical conductivity. 

Such an expert system can also be adapted for the evaluation of data in the published literature. However, this point raises a number of practical questions. A better exploitation of chromatographic data in this field would require an important effort to be made by analysts to constitute standards for quality control and interpretation... 

FIGURE 11.22 Control charts and outliers, (a) pEC50 values (ordinates) run as a quality control for a drug screen over the days on which the screen is run (abscissae). Dotted lines are the 95% c.l. and the solid lines the 99.7% c.l. Data points that drift beyond the action lines indicate significant concern over the quality of the data obtained from the screen on those days, (b) The effect of significant outliers on the criteria for rejection. For the data set shown, the inclusion of points A and B lead to a c.l. for 95% confidence that includes point B. Removal of point A causes the 95% limits to fall below points B, causing them to be suspect as well. Thus, the presence of the data to be possibly rejected affects the criteria for rejection of other data. 

Adequate process control and its associated instrumentation are essential to have product quality control. In some cases the goal is precise adherence to a control point. In others it is simply to maintain the temperature within a comparatively narrow range. 

The Ml test equipment is easy to operate, provides repeatable results, and low cost to operate. It is widely used for quality control and for distinguishing between members of a single family of plastics. Specifically, this MI makes a single-point test that provides information on resistance to flow at only a single shear rate. Because variations in branching or MWD can alter the shape of the viscosity curve, the MI may give a false ranking of plastics in terms of their shear rate resistance to flow. To overcome this problem, extrusion rates are sometimes measured for two loads, or other modifications are made. 

Adequate PC and its associated instrumentation are essential for product quality control. The goal in some cases is precise adherence to a single control point. In other cases, maintaining the temperature within a comparatively small range is all that is necessary. For effortless controller tuning and the lowest initial cost, the processor should select the simplest controller (of temperature, time, pressure, melt-flow, rate, etc.) that will produce the desired results. 

It should be pointed out that when using ethidium bromide the sensitivity of the assays varies depending on the physical state of the nucleic acids (see Table I). Ethidium does not discriminate between RNA and DNA, although dyes are available which bind DNA exclusively, so the relative amounts of each may be determined by taking two sets of measurements. Alternatively, nucleases (DNA-ase or RNA-ase) can be used to exclusively remove one or the other in a mixture. Nucleic acids from different sources (see Table II) also show a variation in sensitivity, and the fluorescence assay lacks the selectivity of the hybridization technique. Nevertheless, for rapid screening or quality-control applications the fluorescence assay is still the method of choice. 

The microbial ecology of water is of great importance in the pharmaceutical industry due to its multiple uses as a constituent of maity products as well as for various washing and cooling processes. Two main aspects are involved the quality of the raw water and any processing it receives and the distribution system. Both should be taken into consideration when reviewing the hazaids to the finished product and aity critical control points. 

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. 

G. Quality control information. All critical points, with recommended control procedures and performance criteria, should be identified. If applicable, stopping point(s) should be indicated. Performance specifications for instruments and standard materials should be included. Recommended actions to be taken if performance does not meet the acceptance criteria need to be provided. Sample handling... 

The Study Director is the pivotal person in any GLP study. The sponsor initiates the study and assigns a Study Director to act as the primary control point for all aspects of the study. The Processing Principle Investigator (PPI) acts as an agent of the Study Director and handles the processing phase of the study. The PPI reports directly to the Study Director, and quality assurance (QA) documents resulting from the processing phase are sent to the Study Director for approval. The Study Director has final say in all questions of compliance with GLP and interpretations of the protocol. The... 

When developing or routinely using an analytical method, quality control (QC) fortifications can be added to each sample at critical points in the procedure to ensure that sensitive steps in the method were conducted properly and to pinpoint where problems occurred if results are less than satisfactory. For example, if the QC fortification samples for detection and cleanup were to show acceptable results in a batch of samples, but the extraction QC spike gave low recovery and/or high variability, then the analyst could modify instrument conditions or altering cleanup parameters immediately. Likewise, if the QC spike added just before analysis gives poor results, then instrument maintenance could be done and the samples merely re-analyzed rather than re-extracted. 

Compositional variations within a single coin issue point to variations in the quality control of the metallurgical processes. 

As an example, this approach was applied to the calculation of the PMF for alanine dipeptide as a function of the two torsion angles

resulting free energy surface is shown in Fig. 4.5. Bilinear Qi elements were used to approximate the free energy. Control points were chosen such that there are four of them around each data point. This was done in order to increase the smoothness and quality of the reconstructed free energy. The position of the Q i nodes and control points is shown in Fig. 4.6. 

The issue of anthelmintic use in poultry production is covered in Chapter 12 and quality assurance systems based on hazard analysis by critical control point (HACCP) systems are described in detail by van Elzakker et al. (2004) and in Chapters 22 and 23 and are therefore not addressed here. 

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