Raw material monitoring

The second approach is one of correlation. A spectral match is calculated by comparing the slope generated from comparative data points on the sample and reference spectra. The cosine between the slopes is calculated and a spectral match index or correlation determined (Fig. 9.23). 

What this actually means is the nearer the spectral match value is to 1.000, the better the correlation. Correlations near 1.000 are generated from spectra that are similar but offset. The lower the index the poorer the correlation, through to -1.000 when the spectra are mirror images (Fig. 9.24). 

I = Reference samples used to construct the product file within a library 

Even this type of testing does not always provide enough information to maintain a robust process. NIR gives an indication of gross particle characteristics 

Spectral match compares the slope between wavelength 1 and 2, and calculates the cosine of the angle between the slopes 

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There are two main reasons for determining biogenic amines in foods (1) their potential toxicity and (2) the possibility to use them as food quality markers (quality control of raw materials, monitoring fermentation processes, process control, etc.) [281]. 

Every manufacturing established shall have a quality control department supervised by approved expert staff directly responsible to the management but independent of other departments. The quality control department shall control all raw materials, monitor all in-process quality checks and control the quality and stability of finished products. 

TG may be used in raw material monitoring. For example, commercial magnesium stearate can comprise various components. In addition to stearate, these primarily include palmitate, their hydrates and free fatty acid. Both TG and DSC curves may be used for characterisation of such samples. 

Modem analytical techniques have not only aided glass producers, but also enabled suppUers of raw materials to produce a more consistent product. Closer monitoring of purity and on-site blending of raw materials are now used by many producers. A stable and uniform raw material is the key to the manufacture of high quaUty glass. 

Hardly a raw material used by the chemical industry has been unaffected by the continuing ripple effect of on-and-off inflation. Raw material prices have not risen evenly. Shifts in relative prices of competing materials continue to occur. Healing with these shifts is a significant challenge to market research and chemical buyer personnel. It must be stressed that a total view of prices, availabiUty, and competing demands is now required and developments must be constandy monitored. 

When low boiling ingredients such as ethylene glycol are used, a special provision in the form of a partial condenser is needed to return them to the reactor. Otherwise, not only is the balance of the reactants upset and the raw material cost of the resin increased, but also they become part of the pollutant in the waste water and incur additional water treatment costs. Usually, a vertical reflux condenser or a packed column is used as the partial condenser, which is installed between the reactor and the overhead total condenser, as shown in Figure 3. The temperature in the partial condenser is monitored and maintained to effect a fractionation between water, which is to pass through, and the glycol or other materials, which are to be condensed and returned to the reactor. If the fractionation is poor, and water vapor is also condensed and returned, the reaction is retarded and there is a loss of productivity. As the reaction proceeds toward completion, water evolution slows down, and most of the glycol has combined into the resin stmcture. The temperature in the partial condenser may then be raised to faciUtate the removal of water vapor. 

Quality Audit. Another important responsibiUty of quahty assurance is the audit function. Using the quahty audit as a tool, QA can monitor the operation of the manufacturing faciUty a toU, ie, contract, manufacturer or raw material suppHer to assure that written procedures are in place and that there is documentation to indicate the procedures are being followed. Properly executed audits allow QA to spot potential weakness in the quahty system that could allow errors to occur. Once identified, these weaknesses can then be corrected before they result in nonconformance. 

Baw material must he utilized. When a production run is scheduled, the necessaiy raw materials must be allocated to the production run. As the individual batches proceed, the consumption of raw materials must be monitored for consistency with the allocation of raw materials to the production run. 

As discussed in Chapter 2, The Toller Selection Process, evaluating the site s safe work practice procedures should have been a part of the review during the toller selection process. Still, new materials may indicate a need to revise or develop special procedures to address unique chemical and physical hazards. New hazards such as vacuum, ciyogenics, ultra-high pressure, or new rotating equipment could be introduced. Medical monitoring requirements or special handling and spill response procedures for the toll s raw materials and products may indicate a need to write or revise safe work practices. 

Are control charts used and monitored for the majority of incoming raw materials ... 

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. 

Assessment of raw materials (purity hidden ingredients supplier monitoring)... 

Has the integrity of raw material, process, and waste storage areas been checked on a regular basis, for example, ground quality monitoring, inspection of tanks, containers, bunds, and so on Provide details and records. Identify the risk category. 

The stream leaving a reactor not only contains the product but may also include a series of by-products, unreacted raw material, solvents and various catalysts, surfactants, initiators, and so on. The unwanted material is removed from the product in a series of separations. Since each separation step is intended to remove certain compounds, the composition of the leaving stream must be monitored and controlled if the product quality is to be maintained constant. In the production of ethylene, c3 compounds, c4 compounds, and Cs compounds are all removed separately and are sold as by-products. Each of these by-product streams must also meet certain specifications and therefore must also be monitored and controlled (see Table 4-1). 

Accurate monitoring of bleaching processes is essential for efficiency, economy and protection of the environment. The importance of checking raw materials, including the substrate, should be obvious. There is also a need to monitor the actual process liquors and to evaluate the results obtained on the substrate. A useful account of such procedures is available [143]. 

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