Question

Question 6 (3 marks) (a) Describe how you could use both graphite furnace atomic absorption spectroscopy (GFAAS) or inductively coupled plasma emission spectroscopy (ICP-AES) to analyse a blood sample that is suspected to contained elevated levels of lead (b) If the same blood sample was also thought to contain high levels of arsenic in addition to lead, which technique would you use? Explain why

Answer 1

AAS is based on the fact that free atoms absorb light at wavelengths characteristic of the element of interest. The amount of light absorbed can be correlated in a linear fashion to the concentration of the analyte in the sample. The lead containing sample is processed by the instrument so as to generate ground-state atoms as a vapour within the light path of the instrument. This process, called atomization, can be done using graphite furnace atomic absorption spectrometry, or GFAAS.

Inductively coupled plasma atomic emission spectrometry (ICP-AES) is another analytical method used for rapid simultaneous determination of seven heavy metals (Cd, Co, Cr, Cu, Mn, Ni and Pb) in human blood fractions, like plasma, cells fraction and whole blood, is performed. Blood samples, such as whole blood, plasma and cells fraction are studied using this techinque. ICP- AES is an emission spectrophotometric technique, which exploits the fact that excited electrons emit energy at a given wavelength as they return to ground state after excitation by high temperature Argon Plasma.

HPLC method can be used to detect high level concentration of Arsenic in the blood smaple. HPLC stands for High performance liquid chromatography which can be used with the help of ICP-MS to find arsenic concentration.