Quality control rules

A pool of plasma is composed by mixing residual amounts of plasma left over from analyses, thereby ensuring the anonymity of the pool sample. Each series of analyses should contain at least one pool plasma sample. The results of 8-10 selected amino acids of the pool are plotted in a Shewhart plot to make deviations from the previously established target values visible. Actions following these deviations will have to be devised by the laboratory staff according to standard quality control rules. 

It cannot be emphasized too strongly that mistakes in sample preparation may cause failure of the whole analytical procedure, even with the most sophisticated instrumentation. This means that not only must the quality control rules be followed but work must be done unhurriedly and with total concentration. 

Parvin CA. Comparing the power of quality-control rules to detect persistent systematic errors. Clin Chem 1992 38 358-63. 

Know and apply safety and quality control rules and procedures. 

Agreement on the NDE plan will be dependent on the extent and relevance of theschedule. Under the amendments proposed to the Rules Surveyors will check that structurally significant welds are included in the shipyard s quality control programme. When agreement has been reached the Surveyor will endorse the plan. 

The Production Department was not amused, because lower values had been expected. Quality Control was blamed for using an insensitive, unse-lective, and imprecise test, and thereby unnecessarily frightening top management. This outcome had been anticipated, and a better method, namely polarography, was already being set up. The same samples were run, this time in duplicate, with much the same results. A relative confidence interval of 25% was assumed. Because of increased specificity, there were now less doubts as to the amounts of this particular heavy metal that were actually present. To rule out artifacts, the four samples were sent to outside laboratories to do repeat tests with different methods X-ray fluorescence (XRFi °) and inductively coupled plasma spectrometry (ICP). The confidence limits were determined to be 10% resp. 3%. Figure 4.23 summarizes the results. Because each method has its own specificity pattern, and is subject to intrinsic artifacts, a direct statistical comparison cannot be performed without first correcting the apparent concentrations in order to obtain presumably true... 

Sample shelves also become overcrowded quickly, but it is often required to keep samples for extended periods of time. Older samples can be stacked into cardboard cartons, clearly identified by laboratory project references or quality control numbers, and stored at a convenient location away from the laboratory. Periodically they should be inspected and the out of date ones eliminated. One word of caution, however. Under current pollution control rules, laboratory samples may not be indiscriminatly disposed of as garbage. The laboratory operator should call in a waste disposal service when in doubt. 

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. 

Control rule-1. To achieve fermention of excellent quality, keep (a) the agitation rate in the first scaling episode (growth phase) > 37 units and (b) the duration of the first episode in the air flowrate < 25 h. 

Control systems will play a key role in future distributed plants ]139,145]. As a rule of thumb, plants will be smaller and simpler, but the control systems will be much more advanced, of a standard not known today. Plant personnel for operation and managing will ultimately no longer be required, except for start-up, shutdown, and services. This is a shift from a regulatory to a servo role, supported by a sophisticated sequence control. Control is needed for safety issues, operability, and product quality control. Sensors have a central role to provide the information needed for control and modeling and simulation is needed for process models. 

If the product is to be used for pharmaceuticals the GMP rules must be obeyed during plant operation. All chemicals to be tested in clinical studies with humans must be prepared according to GMP. This leads to very detailed documentation since if you haven t documented it, you haven t done it . All procedures for manufacturing and changes in procedures are subject to approval by quality control departments. This decreases the flexibility in process development. Products that are contaminated too much must be reprocessed according to the GMP guidelines. All equipment to be used in the pilot plant must be validated before use. 

Westgard jo, Barry PL, Hunt MR (1981) A multi-rule Shewhart chart for quality control in clinical chemistry. Clin Chem 27 493-501. 

In the new vision, assay cycle time is dramatically reduced and the criteria used to measure assay acceptability are matched to sample type. Early screening samples may be assayed using simple methods and minimum numbers of standards. Samples from early preclinical PK studies in rats and other species may require additional standards. Finally, for PK studies performed in the lead characterization phase, one might add quality control (QC) samples. One set of rules for non-GLP assays has been codified in a recent publication.16 These rules make it possible to match the assay cycle time with the in-life cycle time in order to minimize the total discovery cycle time. 

The purpose of the trial also affects the choice of degradation agents and the parameters used to monitor degradation. For comparison and quality control purposes, single agents are most frequently used. For prediction purposes multiple agents are more likely to be representative of service, but at the same time they make extrapolation rules more complicated. The parameters measured in trials to predict lifetime must be those critical to service, but in many instances of comparison or quality checks the choice of parameter can be heavily influenced by experimental convenience. 

The rules for level I (screening) assays are shown in Table 13.1. An example of the type of samples where a level I assay could be used is the CARRS samples [85] that can be used for screening NCEs using a rat PK model [vide supra). The concept behind this assay is that it should use a small number of standards and a simple linear extrapolation. For level II assays (see Table 13.2) that might be used for discovery PK studies in preclinical species, a complete standard curve is required. In this case a complete standard curve is defined as 10-15 standards in duplicate assayed with at least five standards used in the final calibration curve. Neither level I nor level II assays require the use of quality control (QC) standards. When a compound is in the lead qualification stage, then a level III assay would be required. As shown in Table 13.3, the main distinction for level III assays is that they are required to include at least six QC standards. As described in Tables 13.1-13.3, these rules show the requirements for how an assay should be set up before the samples are assayed and then these rules describe the acceptance criteria for the assays after they have been performed. 

Rules and regulations for air quality control and/or solid waste disposal have been established for explosives in general. The regulations vary from state to state (1,3-DNB 1,3,5-TNB). 

Appendix 6 contains requirements of experimental stress analysis. Appendix 8 has acceptance standards for radiographic examination. Appendix 9 covers nondestructive examination. Appendix 10 gives rules for capacity conversions for safety valves, and Appendix 18 details quality-control-system requirements. 

Section 9.2 will review traditional statistical process control/statistical quality control (SPC/SQC) techniques used in quality control. Section 9.3 will follow this review with a discussion of techniques based primarily on an experiential rule base and expert system technology. Section 9.4 will discuss control strategies that use an on-line process model a variety of models can be used in such model predictive control. Section 9.5 will discuss this variety of models. Section 9.6 will summarize this chapter and discusses future trends in the field. 

As can be seen, these SPC/SQC methods provide a means of determining if a process is under control, but they provide little help in the way of taking corrective action should a process not be under control. For the latter, the process engineer usually must determine the quality deviation cause, and determine what—if any—action is necessary to return the process to normal. Prior experience is of considerable value in making this decision. This value led to the investigation of knowledge-based control strategies that relied on a set of control rules derived from prior experience. 

Intralaboratory Quality Control. In its efforts to establish minimum intralaboratory quality control, the USEPA has incorporated certain mandatory quality control practices into each of the 600-series organic methods promulgated as part of final rule making on October 26, 1984 (10). These quality control practices are found in Section 8 of each EMSL method. 

Organic solvents for HPLC are generally very good. There are three rules of thumb to remember always use HPLC grade solvents, buy from a reliable supplier, and filter your solvents and check them periodically with your HPLC. Most manufacturers do both GLC and HPLC quality control on their solvents some do a better job than others. The best way to find good solvents is to talk to other chromatographers. 

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