Cost analysts

In this chapter we examine the processes that have been developed to produce micro-organisms as a source of food protein. We will examine the reasons why micro-organisms have been considered as alternative protein sources, the substrates on which they have been grown, the various process technologies developed and the comparative economics of these processes. One process will be examined in depth, to illustrate how a team composed of such diverse people as microbiologists, process engineers, patent lawyers and cost analysts work together to develop a marketable product. 

The cost of an analysis is determined by many factors, including the cost of necessary equipment and reagents, the cost of hiring analysts, and the number of samples that can be processed per hour. In general, methods relying on instruments cost more per sample than other methods. 

Time, Cost, and Equipment Precipitation gravimetric procedures are time-intensive and rarely practical when analyzing a large number of samples. liowever, since much of the time invested in precipitation gravimetry does not require an analyst s immediate supervision, it may be a practical alternative when working with only a few samples. Equipment needs are few (beakers, filtering devices, ovens or burners, and balances), inexpensive, routinely available in most laboratories, and easy to maintain. 

In the past, commodity chemicals were generally priced on the basis of ROl. Capital cost was the most critical item, and those elements that ate related to capital cost were the principal factors in the selling price (excluding taw material cost in some cases). On this basis, a satisfactory ROl resulted in acceptable values for other criteria such as ROS or sales margin. Many analysts favor ROS as a benchmark for comparison because it is up to date and simple and because it is increasingly difficult to determine a tme ROl based on what profits might be on plants built under indation and expensive capital and constmction costs. 

Another consideration of petroleum assessment analysts is whether, and to what degree, the vast resources of unconventional petroleum in the world can be captured by advances in petroleum production technologies, thereby converting them into conventional sources of petroleum. It is a simple fact that the ia-place resources of petroleum in tar sands, heavy oils, and oil shale can guarantee the future supply of petroleum for hundreds of years at the current rate of consumption, provided they can be produced at competitive costs. 

It is important, however, not to take this analogy too far. In general, the performance of a piece of hardware, such as a valve, will be much more predictable as a function of its operating conditions than will human performance as a function of the PIFs in a situation. This is partly because human performance is dependent on a considerably larger number of parameters than hardware, and only a subset of these will be accessible to an analyst. In some ways the job of the human reliability specialist can be seen as identifying which PIFs are the major determinants of human reliability in the situation of interest, and which can be manipulated in the most cost-effective manner to minimize error. 

Finally, the HRA analyst would calculate the expected frequency of condenser ruptures as a result of improper isolation. The frequency of condenser tube failures is 0.33 per year (1 every 3 years), and the calculated probability of improper isolation is 0.05. Multiplying these two numbers shows the expected frequency of improper isolation of a failed condenser is 0.017 per year, or about once every 60 years. The manager can use this number to help compare the costs and benefits of improvements proposed as a result of the HRA or other studies. 

Another characteristic of the economic-efficiency concept IS that it does not require arbitrai y decisions by the analyst about, fur example, how coal should be evaluated compared with natural gas. The question of whether I Btu of coal is equal to 1, or perhaps 1/2, Btu of natural gas is answered directly by the market. The weightings of the marketplace, revealed in relative prices, vary with scarcity, cost of production, technology, and human preferences. Decisionmakers do not need to think about the underlying reasons, however. They need to know only current prices (and make their best guesses about future prices). 

Expertise required to operate One of the objectives for using microprocessor-based predictive maintenance systems is to reduce the expertise required to acquire error-free, useful vibration and process data from a large population of machinery and systems within a plant. The system should not require user input to establish maximum amplitude, measurement bandwidths, filter settings, or allow free-form data input. All of these functions force the user to be a trained analyst and will increase both the cost and time required to routinely acquire data from plant equipment. Many of the microprocessors on the market provide easy, menu-driven measurement routes that lead the user through the process of acquiring accurate data. The ideal system should require a single key input to automatically acquire, analyze, alarm and store all pertinent data from plant equipment. This type of system would enable an unskilled user to quickly and accurately acquire all of the data required for predictive maintenance. 

An indication has been given in the preceding sections of a number of techniques available to the analytical chemist. The techniques have differing degrees of sophistication, of sensitivity, of selectivity, of cost and also of time requirements, and an important task for the analyst is the selection of the best procedure for... 

The FDA mandates that of all the calibration concentrations included in the validation plan, the lowest jc for which CV < 15% is the LOD (extrapolation or interpolation is forbidden). This bureaucratic rule results in a waste of effort by making analysts run unnecessary repeat measurements at each of a series of concentrations in the vicinity of the expected LOD in order to not end up having to repeat the whole validation because the initial estimate was off by + or - 20% extrapolation followed by a confirmatory series of determinations would do. The consequences are particularly severe if validation means repeating calibration runs on several days in sequence, at a cost of, say, (6 concentrations) x (8 repeats) x (6 days) = 288 sample work-ups and determinations. 

Solution 20-30 calibration points are too many, if only for reasons of expended time. The analyst thus searches for a combination of perhaps n = 8 calibration points and m = 2 replications of the individual samples. This would provide the benefit of a check on every sample measurement without too much additional cost. An inspection of the various contributions in Eq. (2.17) toward the CI(Z) in Table 2.9 reveals the following for n = 8 and m = 2 ... 

The revised database holds over 23 000 analyte values for 660 measurands and 1670 reference materials produced by 56 different producers, from 22 countries. The database is restricted to natural matrix materials (i.e. made from naturally occurring materials, excluding calibration standards manufactured from pure chemicals). Information has been extracted from the relevant certificates of analysis, information sheets, and other reports provided by the reference material producers. As a general rule, the authors have only included in the compilation reference materials for which a certificate of analysis or similar documentation is on file. Information included in the survey is on values for measurands determined in reference materials, producers, suppliers, the cost of the materials, the unit size supplied, and the recommended minimum weight of material for analysis, if available. The new searchable database has been designed to help analysts to select reference materials for quality assurance purposes that match as closely as possible, with respect to matrix type and concentrations of the measurands of interest and their samples to be analyzed see Table 8.3. 

Prior to a method trial, the FDA strongly recommends that a second analyst or independent laboratory perform the method. The independent analyst is asked follow the method SOP as written. This analyst should not have been involved in developing the method or be familiar with it in any way. The purpose of the independent analysis is to determine if a qualified chemist can perform the method described without input other than that provided in the written instmctions. This trial mn will typically identify problems with the SOP that are not apparent to the method developer. Although not required by the FDA, the independent assessment can identify potential problems with the method SOP prior to the lengthy and costly method trial. A trial mn offers the method developer an opportunity to correct problems and to increase the probability that subsequent method trials will be successful. Finally, the method developer should realize that the variability achieved in his/her laboratory is often less than that realized by less experienced analysts. If a method cannot achieve a suitable degree of repeatability in the developer s laboratory, it should not be expected to do any better in other laboratories. 

These requirements have special implications with regard to immunoassay methods. Eirst, the lack of commercial availability of reagents precludes preparing antibody-coated tubes or plates on-site, which may require knowledge of special skills. Commercial availability also ensures the analyst access to a reproducibly manufactured product. Therefore, the method must be based on an immunoassay that is a commercial product. Method developers may choose to introduce an in-house assay to the marketplace by partnering with a manufacturer, although this approach is costly and time-consuming. 

In the modern pesticide residues laboratory, analysts are under ever increasing pressure to (1) increase the range of pesticides which can be sought in a single analysis, (2) improve limits of detection, precision and quantitation, (3) increase confidence in the validity of residues data, (4) provide faster methods, (5) reduce the usage of hazardous solvents and (6) reduce the costs of analysis. 

Specificity is unsurpassed. Traditionally, MS was performed on very large and expensive high-resolution sector instruments operated by experienced specialists. The introduction of low-resolution (1 amu), low-cost, bench-top mass spectrometers in the early 1980s provided analysts with a robust analytical tool with a more universal range of application. Two types of bench-top mass spectrometers have predominated the quadrupole or mass-selective detector (MSD) and the ion-trap detector (ITD). These instruments do not have to be operated by specialists and can be utilized routinely by residue analysts after limited training. The MSD is normally operated in the SIM mode to increase detection sensitivity, whereas the ITD is more suited to operate in the full-scan mode, as little or no increase in sensitivity is gained by using SIM. Both MSDs and ITDs are widely used in many laboratories for pesticide residue analyses, and the preferred choice of instrument can only be made after assessment of the performance for a particular application. 

Industrial analytical laboratories search for methodologies that allow high quality analysis with enhanced sensitivity, short overall analysis times through significant reductions in sample preparation, reduced cost per analysis through fewer man-hours per sample, reduced solvent usage and disposal costs, and minimisation of errors due to analyte loss and contamination during evaporation. The experience and criticism of analysts influence the economical aspects of analysis methods very substantially. 

When using any solvent extraction system, one of the most important decisions is the selection of the solvent to be used. The properties which should be considered when choosing the appropriate solvent are selectivity distribution coefficients insolubility recoverability density interfacial tension chemical reactivity viscosity vapour pressure freezing point safety and cost. A balance must be obtained between the efficiency of extraction (the yield), the stability of the additive under the extraction conditions, the (instrumental and analyst) time required and cost of the equipment. Once extracted the functionality is lost and... 

Advantages Low cost No grinding Broad applicability High b.p. solvent contamination of analyte Low investment Simple equipment Simultaneous extractions in series Low investment Simple equipment Rapid Economic solvent use Good reproducibility Low investment Simple equipment Economical Simple equipment Not traumatic Almost solvent free Concentrated analyte Rapid Low temperatures Rapid Automated Simultaneous extraction Low solvent use Rapid User friendly Automated Sequential extractions Not analyst labour intensive... 

In many cases, the current approach to hyphenation of two (or more) techniques, typically a combination of a separation method and an identification technique (spectroscopic or spectrometric), is still not totally satisfactory. This is especially the case when the optimum operating conditions of both techniques are compromised in their combination. In that respect, any proposed improvement is welcome. Multihyphenated techniques, although fancy, usually become quite complicated, so as to require dedicated analysts. In relation to Scheme 10.2, it should be realised that hyphenated techniques are costly and complex to run they are most useful for unknown analytes. 

The concentration of copper in a sample may be determined by using an iodometric titration or by atomic absorption spectrometry. In each of the following examples, calculate the cost of the assay (assume that the charge for the analyst s time is 50 per hour) ... 

There is no experimentally established optimum frequency for the distribution of samples. The minimum frequency is about four rounds per year. Tests that are less frequent than this are probably ineffective in reinforcing the need for maintaining quality standards or for following up marginally poor performance. A frequency of one round per month for any particular type of analysis is the maximum that is likely to be effective. Postal circulation of samples and results would usually impose a minimum of two weeks for a round to be completed and it is possible that over-frequent rounds have the effect of discouraging some laboratories from conducting their own routine quality control. The cost of proficiency testing schemes in terms of analysts time, cost of materials and interruptions to other work has also to be considered. 

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