Method transfer quality control processes

MDGC, and comprehensive two-dimensional GC, or GCxGC), faster separation techniques (fast GG), fast methods for quality assessment or process control in the flavour area ( electronic noses and fingerprinting MS) and on-line time-resolved methods for analysis of volatile organic compounds (VOGs) such as proton-transfer reaction MS (PTR-MS) and resonance-enhanced multi-photon ionisation coupled with time-of-flight MS (REMPI-TOFMS). The scope of this contribution does not allow for lengthy discussions on all available techniques therefore, only a selection of developments will be described. 

Analytical potency method development should be performed to the extent that it is sufficient for its intended purpose. It is important to understand and know the molecular structure of the analyte during the method development process, as this will facilitate the identification of potential degradation impurities. For example, an impurity of M + 16 in the mass spectrum of a sample may indicate the probability of a nitrogen oxide formation. Upon successful completion of method development, the potency method will then be validated to show proof that it is suitable for its intended purpose. Finally, the method validated will be transferred to the quality control laboratory in preparation for the launch of the drug substance or drug product. 

Because many analytical test methods are expected to ultimately be used in a quality control environment, they require an additional degree of refinement compared to research methods methods for multilaboratory use are also required to be robust. An additional goal of this chapter is to describe validatable, transferable, robust, reliable, accurate, and precise (V-TR AP) methodology, as the validation process requires quality method development. Because validation can be a time consuming, methods should not enter the validation phase unless they are fully developed. The following observations can be made about the relationship between validation and method development ... 

The most common method would be off-line or grab samples, which are taken intermittently and transported to the laboratory for analysis (Figure 9.1(a)). The procedure can be slow and the process may be finished before the results are available. This is more suited to quality control samples taken at the end of the process. Increasingly, samples can be taken at-line (Figure 9.1(b)). These types of samples are also taken intermittently but analysed in an instrument that is very close to the process, i.e. in the plant itself. The next type of sample (on-line samples) are taken from the process (usually automatically) and transferred directly into the analytical instrument for analysis without human intervention (Figure 9.1(c)). Pretreatment of the sample may also be carried out automatically as part of the assay. 

Information on specific production methods can be found in the literature [Pinna 1998]. Impregnated catalysts are mainly produced batchwise with discontinuous process steps. Therefore, continuous quality control of the individual catalyst batches is vital (e.g., testing of mechanical strength, performance tests in screening reactors). The process developer must pay special attention to transferring the laboratory recipe to industrial catalyst production. Test production should be carried out relatively early... 

Manufacturing methods for composites vary from manual to fully automated processes, whereby the latter have better quality control than the former. Wet layup, pultrusion, and filament winding are all discussed in some detail, while other techniques such as pull-winding, resin transfer moulding, vacuum bag moulding, and injection moulding are left to specialized composite materials texts. 

The examples presented here for the screening of fruit juices can also be seen as proof-of-principle for other upcoming applications. The same workflow (preparation, measurement, processing, reporting) and underl)dng mathematical methods can be easily transferred to other quality control applications, such as the screening of milk, wine or beer. 

OSP thickness is normally determined by indirect sampling. No method exists for determining the OSP thickness dnring prodnction on the actual PCB. Instead, a sample coupon is processed along with the prodnction parts. The conpon is immersed in an acid/solvent solution that dissolves the coating. The solntion is transferred to a UV-VIS cell, where the absorbance of light allows the estimation of the thickness of OSP on the coupon. That measurement is used as a quality control for the prodnction boards. 

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