Lining applications technology

A true on-line application of NMR that is widely used in the held and based on this unilateral NMR technology is downhole NMR sensing performed by the gas and oil exploration and production companies such as Schlumberger, Halliburton, Baker Hughes, and Chevron. These tools are typically provided as a... 

The implementation costs of FTIR instrumentation, especially for on-line applications can be very high, sometimes in excess of US 100 000. Also, there are issues relative to size, performance and still the physical reliability issues that make FTIR less than acceptable for many areas of application. Furthermore, there is a general desire to make instrumentation much smaller, and even handheld and portable (one example is shown in Figure 4.4). As a result, today we are seeing a number of new competing technologies. In some cases these are direct competition to FTIR, but in others there are often compromises between size and/or performance, and overall versatility. FTIR is a very versatile approach to spectral measurement. However, such versatility is often not required for specific applications, and it is in such cases that alternative technologies can often excel. 

One indication of the developing interest in PATs in the pharmaceutical area is the number of book chapters and review articles in this field that have appeared in the last few years. Several chapters in The Handbook of Vibrational Spectroscopy3 are related to the use of various optical spectroscopies in pharmaceutical development and manufacturing. Warman and Hammond also cover spectroscopic techniques extensively in their chapter titled Process Analysis in the Pharmaceutical Industry in the text Pharmaceutical Analysis.4 Pharmaceutical applications are included in an exhaustive review of near-infrared (NIR) and mid-infrared (mid-IR) by Workman,5 as well as the periodic applications reviews of Process Analytical Chemistry and Pharmaceutical Science in the journal Analytical Chemistry. The Encyclopedia of Pharmaceutical Technology has several chapters on spectroscopic methods of analysis, with the chapters on Diffuse Reflectance and Near-Infrared Spectrometry particularly highlighting on-line applications. There are an ever-expanding number of recent reviews on pharmaceutical applications, and a few examples are cited for Raman,7 8 NIR,9-11 and mid-IR.12... 

A wide variety of particle si2e measurement methods have evolved to meet the almost endless variability of industrial needs. For instance, distinct technologies are required if in situ analysis is required, as opposed to sampling and performing the measurement at a later time and/or in a different location. In certain cases, it is necessary to perform the measurement in real time, such as in an on-line application when size information is used for process control (qv), and in other cases, analysis following the completion of the finished product is satisfactory. Some methods rapidly count and measure particles individually other methods measure numerous particles simultaneously. Some methods have been developed or adapted to measure the size distribution of dry or airborne particles, or particles dispersed in Hquids. 

The gas chromatograph is not only capable of meeting the needs for on-line applications but also provides several additional features. Technological advancements in both rtticro-packed colurtms and microprocessors have allowed the developmerrt of very powerful and flexible on-line gas chroma tographs. 

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