Get a look at images, photos, videos, and animations that encompass many facets of teaching and learning about analytical chemistry.
In ion-exchange chromatography (IEC) the stationary phase is a cross-linked polymer resin, usually divinylbenzene cross-linked polystyrene, with covalently attached ionic functional groups. As shown here for a styrene–divinylbenzene co-polymer modified for use […]
The figure below provides a block diagram of a typical liquid chromatography-mass spectrometer (LS–MS) instrument. As illustrated here, a three component mixture is injected onto the HPLC. When component A elutes from the column, […]
Another common group of HPLC detectors are based on electrochemical measurements such as amperometry, voltammetry, coulometry, and conductivity. The illustration below, for example, shows an amperometric flow cell. Effluent from the column […]
One popular HPLC detector takes advantage of an analyte’s UV/Vis absorption spectrum. These detectors range from simple designs, in which the analytical wavelength is selected using appropriate filters, to a modified spectrophotometer […]
The operating pressure of an HPLC is sufficiently high that we cannot inject the sample into the mobile phase by inserting a syringe through a septum (as we can do in gas […]
A typical HPLC includes between 1–4 reservoirs for mobile phase solvents. The mobile phase solvents are pulled from their reservoirs by the action of one or more pumps. Shown here is a close-up […]
The illustration below shows the gradient elution separation of a mixture of flavonoids. Mobile phase A is an aqueous solution of 0.1% formic acid and mobile phase B is 0.1% formic acid […]
One strategy for finding the best mobile phase for an HPLC separation is to use the solvent triangle, which allows us to explore a broad range of mobile phases with just seven […]
The most common type of HPLC column is a stainless steel tube with an internal diameter between 2.1 mm and 4.6 mm and a length between 30 mm and 300 mm. The […]
The photo below shows an example of a typical HPLC instrument with insets showing close-up views of the pumps that move the mobile phase through the system, and the plumbing used to inject […]
In a GC analysis the area under the peak is proportional to the amount of analyte injected onto the column. The peak’s area is determined by integration, which usually is handled by […]
The figure below provides a block diagram of a typical gas chromatography-mass spectrometer (GC–MS) instrument. As illustrated here, a three component mixture enters the GC. When component A elutes from the column, it enters […]
