High-performance liquid chromatography data, analysis

Figure 21.6 shows the kinetic profile under the actual process conditions. The reaction profile (combination of the anion and free acid of 3 versus time) obtained by high-performance liquid chromatography (HPLC) analysis also matched the onfine IR data. Again, the use of online IR coupled with principal component analysis provided the means to profile HA and A during the reaction. Formation of the free acid form 3 (HA) was immediately observed upon addition of a catalytic amount of TFA. This clearly shows that constant liberation of the free acid form HA... 

High-performance liquid chromatography (HPLC) is one of the premier analytical techniques widely used in analytical laboratories. Numerous analytical HPLC analyses have been developed for pharmaceutical, chemical, food, cosmetic, and environmental applications. The popularity of HPLC analysis can be attributed to its powerful combination of separation and quantitation capabilities. HPLC instrumentation has reached a state of maturity. The majority of vendors can provide very sophisticated and highly automated systems to meet users needs. To provide a high level of assurance that the data generated from the HPLC analysis are reliable, the performance of the HPLC system should be monitored at regular intervals. In this chapter some of the key performance attributes for a typical HPLC system (consisting of a quaternary pump, an autoinjector, a UV-Vis detector, and a temperature-controlled column compartment) are discussed [1-8]. 

Surfactin in the supernatant was confirmed and the concentration determined by high-performance liquid chromatography analysis as described by Noah et al. (4). Surface tension was measured using video image analysis of inverted pendant drops as previously described (5). All data points are an average of five measurements taken of the cell-free supernatant. 

Principal component analysis is most easily explained by showing its application on a familiar type of data. In this chapter we show the application of PCA to chromatographic-spectroscopic data. These data sets are the kind produced by so-called hyphenated methods such as gas chromatography (GC) or high-performance liquid chromatography (HPLC) coupled to a multivariate detector such as a mass spectrometer (MS), Fourier transform infrared spectrometer (FTIR), or UV/visible spectrometer. Examples of some common hyphenated methods include GC-MS, GC-FTIR, HPLC-UV/Vis, and HLPC-MS. In all these types of data sets, a response in one dimension (e.g., chromatographic separation) modulates the response of a detector (e.g., a spectrum) in a second dimension. 

Inductively coupled plasma mass spectrometry (ICP-MS) is one of the most significant analytical advances to occur in the last 20 years as it allows multielement analysis of solutions and solids to be performed at subnanogram concentrations. Instrumental advances have occurred such that Quadrupole (Q) ICP-MS units are now in routine use in many laboratories. In this chapter, the use of Q-ICP-MS and high performance liquid chromatography (HPLC)-ICP-MS is discussed as regards the quantification of total As and As species in seafood. To highlight the strengths and weaknesses of the use of ICP-MS, data are used that were mainly produced in the laboratories of the authors of this chapter. 

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