Metal Analysis

Question 1

What is ICP-MS?

Answer 1

Inductively coupled plasma mass spectrometry.
current ionizes sample. Plasma with ions in gas phase, shoot charged ions into MS and analyse with very high sensitivity. PPtrillion or below.

Question 2

How does flame analysis work?

Answer 2

Metals exhibit different colours due to specific wavelength. Analyse colour of flame to determine composition of metal ions.

Question 3

How is zinquin ester used to image zinc in the hippocampus?

Answer 3

Shows distribution of ions rather than total metal.
Fluorophore = zinquin ester cleaved off in cell –> becomes carboxylate which can coordinate zinc ION, then compound fluoresces.
Shows high [] zinc in hippocampus.

Question 4

Give examples of the concentrations of free divalent metal ions in the cell.

Answer 4

Mg2+ = 1 mM
Ca2+ = 1uM
Zn2+ = 1 pM – 1nM
Cu2+ = 1 aM – 1fM 
(cover 15 orders of magnitude!!)

Question 5

What is the use of isotope fractionation?

Answer 5

Tissues fractionate isotopes. Lighter and heavier isotopes of same elements are taken up differently.
Cancer has different set of transporters so will fractionate elements slightly differently.
Isotope composition can be used in diagnostics.