step-up year 1 practical laboratory session: iron analysis

Step-Up Year 1

Practical Laboratory Session: Iron Analysis

Iron (Fe)

Iron is vital for a number of physiological processes

Occurs naturally in food sources

Also occurs naturally in our water

Iron in our water

Should we be concerned?

Iron in water is found in two forms: - Ferrous (Fe2+)- Ferric (Fe3+)

Fe3 + 3H2O Fe(OH)3 + 3H+

Iron in our water

A range of solutions from no iron to high iron content

Ferrous iron in water has addedto it thiocyanate (SCN)

Fe(SCN)(H20)5]2+

Iron in our water How do we decide what

should be classed as ‘low’ or ‘high’ iron content?

Calibration Curve – our baseline to compare against

Iron Analysis

Using a Spectrophotometer at a wavelength 490nm to measure Absorbance (nm)

Using the calibration curve, we can determine unknown

Iron Concentrations

Before you start

Read the protocol thoroughly

?AnyQuestions

Always read the protocol before you start and follow H&S

Remember Beer-Lambert Law

Absorbance = ε.c.l

where ε = constantc = concentrationl = path length through solution