Numbers of Atoms Archive

This Numbers of Atoms series will explore spectroscopy – the interaction of matter and radiated energy – as a powerful tool for qualitative and quantitative analysis.  The radiated energy involved is usually electromagnetic radiation, but it can also be radioactive nuclei or magnetic fields.  Matter interacts with this energy by absorbed or scattered it, or […]

Numbers of Atoms: Real chemists still do titrations

Posted July 5, 2013 By Marc Leger

In our last Numbers of Atoms post, we considered volumetric analysis – a simple approach to quantitative analysis that allows for relatively quick determination of the concentration of an analyte in a solution. In a titration, a quantity of reactant (the titrant) is added to a known quantity of a sample in solution, until all of […]

Not all analytical chemistry requires high-tech equipment.  We sometimes forget that analytical chemistry existed before modern instrumentation, computers and even electricity.  A quick and simple way to find the concentration of an analyte is to make it react with a solution of known concentration of another compound.  After confirming that all of the analyte has […]

We conclude (for now) our look at chromatography for separations and quantitative analysis by considering instruments that offer even more sensitivity and selectivity than the high-performance liquid chromatography (HPLC) methods described in the last post. But you said that HPLC can give detection limits in the parts-per-billion range.  That seems really low…  Can we really […]

Our last post was an introduction to some chromatographic approaches for separating compounds in a mixture.  The methods described there were, if we can say, “manual” – just the stationary and mobile phases, the sample, and nature doing the work with gravity or capillary action.  We concluded the discussion with column chromatography, and some interesting questions […]