LC-MS Detection
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, […]
Image and Video Exchange
Get a look at images, photos, videos, and animations that encompass many facets of teaching and learning about analytical chemistry.
Electrochemical Detector for HPLC Separations
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 […]
Absorbance and Fluorescence Detection for HPLC Separations
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 […]
Loop Injector for HPLC
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 […]
HPLC Pumps
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 […]
Gradient Elution Separation of Flavonoid Mixture
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 […]
Using a Solvent Triangle to Optimize an HPLC Separation
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 […]
HPLC Column
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 […]
HPLC Instrumentation
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 […]