Components, LABs utilization

Consider one small molecule, phenylalanine. It is an essential amino acid in our diet and is important in protein synthesis (a component of protein), as well as a precursor to tyrosine and neurotransmitters. Phenylalanine is one of several amino acids that are measured in a variety of clinical methods, which include immunoassay, fluorometry, high performance liquid chromatography (HPLC see Section 4.1.2) and most recently MS/MS (see Chapter 3). Historically, screening labs utilized immunoassays or fluorimetric analysis. Diagnostic metabolic labs used the amino acid analyzer, which was a form of HPLC. Most recently, the tandem mass spectrometer has been used extensively in screening labs to analyze amino acids or in diagnostic labs as a universal detector for GC and LC techniques. Why did MS/MS replace older technological systems The answer to this question lies in the power of mass spectrometer. 

At the end of the f 990s, with an eye toward deregulation of the utility market and the possible breakup of large centralized electric utilities, many companies6 in North America, Europe, and Japan are competing to develop small stand-alone fuel cell systems and components, usually powered by natural gas. A partial list includes Avista Labs, H Power Corporation, Plug... 

An ideal on-site detection system would be inexpensive, sensitive, fully automated, reliable, multiplex sample handling, and detect a broad range of explosives. The advent of microfluidic lab-on-a-chip technology might offer such a detection system. Microfluidic capillary electrophoresis chips have been utilized for the detection of nitroaromatics such as TNT, DNT, NT, and DNB [9-12]. Due to the good redox properties of nitroaromatics and the inherent suitability for miniaturization, most of the microfluidic methods so far used electrochemical methods for detection. The individual components of nitroaromatics can be detected in the capillary electrophoresis chips (analyte-specific) unlike the colorimetric methods (class-specific) where nitroaromatics are detected broadly. 

The emerging use of microfluidic fuel cells and batteries for analytical applications and educational purposes is also encouraging. The low cost, fabrication flexibility, and unique visualization capabilities inherent to microfluidic cells make them well suited as instructional tools to engage students in the classroom, potentially for a wide variety of courses in the areas of energy conversion and storage, applied chemistry, and microsystems. For analytical applications, standardized units could be produced as a convenient, low-cost platform for in situ lab-scale testing and characterization of electrochemical cell components such as novel electrocatalysts, catalyst supports, and bioelectrodes. Overall, microfluidic electrochemical cells may come to serve equally important functions as analytical and educational tools in addition to commercial utility. 

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