Quick quality control

We have also applied ELISA to several biological pesticides including the endotoxin of Bacillus thurineiensis kurstaki (Btk). In this application to a macromolecular analyte, we have used a double antibody sandwich ELISA for Btk to measure the amount of ELISA reactive material in formulations of the pesticide. Figure 7 shows the use of an ELISA standard curve of gel purified Btk endotoxin to measure the immunoreactive material in dilutions of two Btk formulations. It has been demonstrated that ELISA can serve as a quick quality control check for formulations of Bacillus thurineiensis lsraelensis (44). Such examples indicate that immunoassays will be increasingly important as biologicals and products of recombinant DNA research impact our field (M) ... 

Prior to interpreting the ECG it is helpful to perform some quick quality control checks (As discussed in Chap. 3). A brief check should ensure the ECG was recorded under normal parameters, and if not that you as the interpreter are aware of any changes made during the recording process. Checks should include ... 

The hydraulic or Carver press is commonly used to determine oil for quick quality control purposes. A ground sample is placed in a chamber for mechanical-pressing extraction. After the pressing cycle is completed, the free oil or the partially defatted snack sample is weighed. The instrument should be calibrated for each type of snack because each type leaves different amounts of residual oil (around 12% oil). Values should be correlated with solvent extraction values. 

It is often important in practice to know when a process has changed sufficiently so that steps may be taken to remedy the situation. Such problems arise in quality control where one must, often quickly, decide whether observed changes are due to simple chance fluctuations or to actual changes in the amount of a constituent in successive production lots, mistakes of employees, etc. Control charts provide a useful and simple method for dealing with such problems. 

The purpose for which the analytical data are required may perhaps be related to process control and quality control. In such circumstances the objective is checking that raw materials and finished products conform to specification, and it may also be concerned with monitoring various stages in a manufacturing process. For this kind of determination methods must be employed which are quick and which can be readily adapted for routine work in this area instrumental methods have an important role to play, and in certain cases may lend themselves to automation. On the other hand, the problem may be one which requires detailed consideration and which may be regarded as being more in the nature of a research topic. 

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. 

Chemical analysis finds important applications in the quality control of industrial processes. In an ideal situation a continuous analysis of the process stream is made and some aspects of this are discussed in Chapter 12. However, such continuous analysis is by no means always possible, and it is common to find a process being monitored by the analysis of separate samples taken at regular intervals. The analytical data thus obtained need to be capable of quick and simple interpretation, so that rapid warning is available if a process is going out of control and effective corrective action can be taken. 

In the past, laboratories have justified the initial investment in dedicated automation on the basis of the large number of identical, repetitive operations carried out. Fixed or dedicated automation is utihzed for large quantities of standard procedures, such as those found in manufacturing environments or in clinical laboratories. Fixed automation follows a predetermined sequence of steps to perform a defined procedure although efficient, it can only perform one repetitive procedure. Robotics, however, can provide flexible automation to meet the changing needs typical of quality control and research laboratories. Flexible automation is programmed by individual users to perform multiple procedures, and can be quickly reprogrammed to accommodate new or revised procedures. In these situations, a careful assessment of the software overhead must be made before a decision to purchase is made. 

First of all, before we compare flow reactors, let us mention the batch reactor briefly. The batch reactor has the advantage of small instrumentation cost and flexibility of operation (may be shut down easily and quickly). It has the disadvantage of high labor and handling cost, often considerable shutdown time to empty, clean out, and refill, and poorer quality control of the product. Hence we may generalize to state that the batch reactor is well suited to produce small amounts of material and to produce many different products from one piece of equipment. On the other hand, for the chemical treatment of materials in large amounts the continuous process is nearly always found to be more economical. 

Proper Use of Equipment. Are personnel schooled in the proper techniques of equipment use Do they use check lists for operation of complicated machinery Will they report their own mistakes quickly so that the situation can be corrected before more damage is done Silent covering of human mistakes has ruined many gallons of wine. Build trust in the workers for your quality control effort and attempt to remove fear of being caught in a mistake. 

The apparatus used to measure membrane bubble points is shown in its simplest form in Figure 7.7 [4], Bubble point measurements are subjective, and different operators can obtain different results. Nonetheless the test is quick and simple and is widely used as a manufacturing quality control technique. Bubble point measurements are also used to measure the integrity of filters used in critical pharmaceutical or biological operations. 

The melt flow indexer. The melt flow indexer is often used in industry to characterize a polymer melt and as a simple and quick means of quality control. It takes a single point measurement using standard testing conditions specific to each polymer class on a ram type extruder or extrusion plastometer as shown in Fig. 2.45. 

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