Selecting specific ions for analysis in flame photometry

At BWB Tech, we use flame photometry to measure how bright light appears to the human eye.

We use photometry to analyse Sodium, Potassium, Calcium, Barium and Lithium.

All of these are of the period of alkali or alkaline earth metals in the periodic table.

It is also possible to analyse other elements in these two periods of the periodic table.

Due to the rarity of these elements for the standard applications our customers purchase them for, though, they end up being unused.

Our team can, however, help in selecting and customising a photometer for your own personal needs.

What other ions can be analysed by flame photometry?

There are a number of other ions which could be useful to analyse with flame photometers.

They include Lead, Arsenic and other toxic metals which can be found from chemical run-offs.

The location of the leak can be found by tracking the concentration as it increases up a water source.

However, it is just not feasible to do so, and here’s why.

What makes an element suitable to analyse with a photometer?

When using a flame photometer, increasing the temperature of the flame increases the quantity of emitted wavelengths.

It does this by increasing the ratio of unexcited atoms to excited atoms.

Elements in the alkali or alkaline earth metals periods only have two electrons in the outer shell.

Therefore, they require far less energy to remove that the other elements of the periodic table.

As you move across from left to right of the periodic table, the amount of energy to excite an atom increases massively.

This increase of energy required reduces the ratio of excited to ground state ions.

It also adds further jumps, which emits more numerous wavelengths, thus diluting the intensity of the single wavelength that the photometer’s photodiode analyses to determine the concentration.

When is an element not suitable to analyse with a photometer?

If the application you want requires the analysis of multiple ions (10-plus elements) or elements found on the far right of the periodic table in the metalloids or transition metal groups, you should consider ICP (Inductively Coupled Plasma) analysis.

Due to the plasma forming at such a high temperature, all the electrons from the ion are stripped. So, the heat required to analyse these elements is possible.

A flame photometer is the quickest and easiest method to analyse five elements in fields such as medicine biology and chemistry.