Faster Analysis Times

Let us take a more detailed look at each of these approaches. 

There are a number of these enhanced productivity sampling systems on the market, all of which work in a slightly different way. However, they all have one thing in common, and that is they offer at least a two-fold reduction in analysis time compared to traditional autosamplers. Some of the other benefits associated with this time saving include  

Improved precision due to no pulsing from peristaltic pump 

Better accuracy due to online dilution and addition of internal standards 

Constant flow of solutions to plasma reduces stabilization times 

---

In practice, the GC conditions should be designed to give the shortest analysis time while still providing the necessary selectivity (i.e., separation of both analyt-analyte and matrix-analyte). Selective detectors often have fast data collection rates and improved matrix-analyte selectivity, but analyte-analyte selectivity must be addressed solely by the GC separation. MS can improve both types of selectivity and, by reducing the reliance on the GC separation, faster analysis times can often be achieved in complicated mixtures. 

Chemists in its Methods of Analysis, 8th ed. Methods have also been developed for DON by TLC (93) and for several trichothecenes both by immunoassay (94,95) and by supercritical fluid chromatography (96). In comparison with LC, supercritical fluid chromatography is characterized by sharper peaks and faster analysis times, similar to those obtained by capillary GC. 

The analysis of some primary mono- and diamines with a standard amino-acid analyzer was attempted using a column material consisting of Zeocarb 226-4.5% DVB [27]. This stationary phase provides a good separation and a faster analysis time than obtained previously for amines and diamines [28]. 

Multielement determination (sequential or simultaneous) faster analysis time minimal chemical interaction detection limits and sensitivity fall in between that of flame and graphite furnace measurements. 

Since high solute dlffusivity, lower viscosity and excellent solvating properties can be obtained with supercritical fluids, higher chromatographic efficiencies and faster analysis time than liquid chromatography can be obtained with SFC (21). It is also possible to separate non-volatile high molecular weight compounds at relatively low temperatures. 

Comparison studies between luminol detection and BCD for PAN analysis have shown that either method can yield accurate, reliable, sensitive measurements of ambient PAN concentrations, with typical sensitivities on the order of 10 ppt. The advantages of the luminol detector over GC/ECD lie in the faster analysis times achievable. This makes luminol an attractive alternative for aircraft measurements, where time resolution translates into spatial resolution. The luminol detector also enables the simultaneous measurement of PANs and NO2 to monitor decomposition and formation processes in the atmosphere." " ... 

In recent years, there has been a trend to develop ever smaller liquid chromatography systems. LC systems on micro and even nanoscales have been demonstrated. Shorter and smaller columns with smaller particles offer faster analysis times, decreased solvent consumption and require less sample. The differences between preparative, analytical, micro and nano LC are summarised in Table 2.2. 

These advantages are a) faster analysis time, b) increased accuracy and smaller standard deviation in quantitative analysis, c) precise determination of retention data with Kovdts indices in qualitative analysis, d) increased utility of instruments, e) improvement and application of new techniques which cannot be used without a computer, and f) more information overall. Each of these improvements is a step forward in the progress of analytical science and technology, some of which, however, will earn their keep only in the future. 

In liquid chromatography greater efficiencies and faster analysis times have resulted from the use of smaller particle diameters, within the pressure limitations imposed by instrumentation and support materials. While HPLC has demonstrate improved column efficiencies due to the use of superior support properties, the low-pressure modihed-cellulose and liquid-coated materials have often shown superior selcctivities with regard to nu cleic acid compounds. 

The CZE analysis of Tf seems to be an alternative to CDT measurements kits, which are prone to inaccurate diagnostics. Normal CDT ranges are method-dependent and, consequently, results must be interpreted by taking into account method-specific cutoff values [176,184], In any case, several authors support the application of CZE for CDT determination in the clinical laboratory [191] and claim that it represents an alternative to HPLC and that it should be taken into account as a reference method for CDT [67], In comparison to HPLC, CZE methods have the advantages of easier sample preparation, faster analysis times, higher isoforms resolution, and faster column reconditioning [197],... 

Both techniques share the same principles of fractionation on the basis of crystallizability. TRFF is carried out in a packed column and demands two full temperature cycles, crystallization and elution (dissolution), to obtain the analysis of the composition distribution. In CRYSTAF, the analysis is performed in a single step, the crystallization cycle, which results in faster analysis time and simple hardware requirements. 

AFS is well suited to speciation because of its simple instrumentation and excellent sensitivity. Instrumentation typically consists of either gas chromatography (GC) or high-performance liquid chromatography, to separate the various chemical species, with the AFS instrument serving as the detector. GC has the advantages of higher sensitivity and faster analysis times, but it is limited to volatile and thermally stable compounds. 

When compared to conventional GG, the primary objective of fast GC is to maintain suf cient resolving power in a shorter time, by using adequate columns and instrumentation in combination with optimized run conditions to provide 3 10 times faster analysis times [46-48]. The technique can be accomplished by manipulating a number of analysis parameters, such as column length, column internal diameter [ID], stationary phase, Im thickness, carrier gas, linear velocity. 

Electroendosmosis is probably the most important factor in faster analysis time and better resolution effected by capillary electrophoresis. Therefore, electroendosmosis deserves a detailed consideration. 

---