Instant Notes: Analytical Chemistry

The separation of a series of n-alkanes isothermally at 150°C on a packed column is shown in Figure 1(a), and illustrates the fi ...

Two potential disadvantages of temperature programming are the inevitable delay between consecutive chromatographic runs while t ...

Methods of identifying unknown solutes separated by chromatographic tech- niques are described in Topic D2. In the case of gas c ...

series of n-alkanes, defines an index for each alkane as 100 ¥the number of carbon atomsfor any column at any temperature, i.e. ...

carbon number by interpolation (Fig. 4). For an unknown solute, its Kováts index can then be checked against data bases by compu ...

Section D – Separation techniques D6 HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY: PRINCIPLES AND INSTRUMENTATION Key Notes High-perfo ...

Principles High-performance liquid chromatography(HPLC) is a separation technique where solutes migrate through a column contain ...

mined by its overall polarity, the polarity of the stationary phase and the nature of the sample components. Unlike a GCcarrier ...

● Solvent reservoirswith in-line filters(2mm porosity or less) for each solvent to remove dust and other particulate material. T ...

types of HPLC column, conventional and microbore, and a comparative summary is given in Table 2. Microbore columns have three pr ...

peaks on bonded phase silicas because of adsorptive interactions with residual silanols and metallic impurities in the silica. T ...

D6 – HPLC: principles and instrumentation 161 Si OH CISi CH 3 CH 3 R Si OH Si O Si CH 3 CH 3 R Si OH (a) (b) Si O Si CH 3 + CISi ...

Solute detection Detectors are based on a selective responsefor the solute, such as UV- absorbanceor fluorescence, or on a bulk ...

versatile as they allow monitoring at any wavelength within the working range of the detector to give the optimum response for e ...

● Fluorescence detectorsare based on filter-fluorimeters or spectrofluori- meters. They are more selective and can be up to thre ...

Conductance monitorsare used in ion chromatography, a mode of HPLC useful for separating low levels of inorganic and organic ani ...

Section D – Separation techniques D7 HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY: MODES, PROCEDURES AND APPLICATIONS Modes of HPLC Al ...

order of increasing polarity. This mode is not used extensively, but is suitable for mixtures of structural isomers and solutes ...

ODS and other hydrocarbon stationary phases will separate many mixtures, and are invariably a first choice in developing new HPL ...

Ion-exchange chromatography is not that widely used. Inorganic ions and some cations are better separated by a related mode know ...