Column technology, advances

The indirect liquefaction basehne design is for a plant of similar size. Unhke the direct hquefaction basehne, the design focuses on producing refined transportation fuels by use of Sheh gasification technology. Table 27-17 shows that the crude oil equivalent price is approximately 216/m ( 34/bbl). Additional technological advances in the production of synthesis gas, the Fischer-Tropsch synthesis, and product refining have the potential to reduce the cost to 171/m ( 27/bbl) (1993 US dollars), as shown in the second column of Table 27-17. 

SynChropak GPC supports were introduced in 1978 as the first commercial columns for high-performance liquid chromatography of proteins. SynChropak GPC columns were based on research developed by Fred Regnier and coworkers in 1976 (1,2). The first columns were only available in 10-yu,m particles with a 100-A pore diameter, but as silica technology advanced, the range of available pore diameters increased and 5-yu,m particle diameters became available. SynChropak GPC and CATSEC occasionally were prepared on larger particles on a custom basis, but generally these products have been intended for analytical applications. 

Fast chromatography involves the use of narrow-bore columns (typically 0.1-mm i.d.) that will require higher inlet pressures compared with the conventional wide-bore capillary columns. These columns require detectors and computing systems capable of fast data acquisition. The main disadvantage is a much-reduced sample loading capacity. Advances in GC column technology, along with many of the GC-related techniques discussed below, were recently reviewed by Eiceman et... 

Recent advances in capillary column technology presume stringent performance levels for the other components of a gas chromatograph as column performance is only as good as that of the rest of the system. One of the most important factors in capillary column gas chromatography is that a high repeatability of retention times be ensured even under adverse ambient conditions. 

Since the introduction of gel-permeation chromatography (GPC) in the 1960 s, there have been tremendous advances in polymer gel size-exclusion column technology. Polystyrene-divinyl benzene copolymer gels, and the techniques by which they are packed into columns, have improved to the point where commercial columns exhibit up to 50,000 plates/meter. These lO-ym gels are sufficiently rugged to permit flow rates of up to 3.0 ml/minute... 

Advanced column technology could also be useful in the development ol very efficient culuimis in tei ins of plate nutnbet. Figure 11 shows that it... 

HPLC instrumentation and column technology have undergone major advances since the early 1970s, when HPLC made its debut in the field of vitamin analysis. Yet sample preparation in food analysis continues to rely largely on manual wet-chemical techniques, which are time consuming and labor intensive, require considerable analytical skill, and constitute the major source of error in the assay procedure. There is also the serious problem of environmental pollution and the exposure of laboratory personnel to toxic chemicals. 

Advances in Sample Preparation/Cleanup and Column Technology 46... 

ADVANCES IN SAMPLE PREPARATION/CLEANUP AND COLUMN TECHNOLOGY... 

Recent advances in circuit miniaturization and column technology, the development of microprocessors and new concepts in instrument design have allowed sensitive measurement at the parts per billion and parts per trillion levels for many toxicants. This increased sensitivity has focused public attention on the extent of environmental pollution, because many toxic materials present in minute quantities could not be detected until technological advances reached the present state of the art. At present, most pollutants are identified and quantified by chromatography, spectroscopy, and bioassays. 

Column Technology. Increased sensitivity and component resolution have resulted from advances in solid-state electronics and column and detector technologies. In the field of column technology, the capillary column has revolutionized toxicant detection in complex samples. This column generally is made of fused silica 5 to 60 m in length with a very narrow inner diameter (0.23-0.75 mm) to which a thin layer (e.g., 1.0 11 in) of polymer is bonded. The polymer acts as the immobile or stationary phase. The carrier gas flows through the column at flow rates of 1 to 2 ml/min. 

The options we enumerate for improving efficiency of a column are by no means exhaustive or unique. We simply state them here to alert the reader of possible improvement options. We note that "cookbook" techniques to improve efficiencies are foredoomed to obsolescence since technology advances and they do not capture "out-of-the-box" solutions, which can shift paradigms. 

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