Techniques used to detect trace elements

Question 1

What are radioisotopes

Answer 1

radioactive isotopes of an element
- same number of protons but different neutrons

Question 2

Wehn radioisotopes decay to become stable it gives off some of the excess energy as gamma rays or subatomic particles (alpha or beta). What happens when it emits alpha or beta particles?

Answer 2

becomes a new element
- alpha particles = helium nuclei (2 protons and 2 neutrons)
- beta particles = electrons

Question 3

Example of high radioisotope Zn65 can detect zinc metabolism

Answer 3

1. trace amounts of Zn65 added to culture medium
2. cells take up Zn65 in medium
3. wash cells to give pellet which you can measure the radioactivity of the pellet

lower radioactivity = zinc metabolism occurring

Question 4

How does atomic absorption spectrophotometry work?

Answer 4

1/ spray solution containing element into a flame to be atomised
2. atomised element passes through a beam of light
3. measure reduction of intensity of light due to element absorption at particular wavelengths
- through the use of special lamps which produce lights at particular wavelengths

Question 5

How can atomic absorption spectrophotometry be used to detect trace elements

Answer 5

atoms of elements are absorbed at specific wavelengths and the absorption is proportional to amount of element present.
Then using standard solutions can construct a calibration curve to see where the sample concentration

Question 6

How does inductively coupled plasma mass spectrometry (ICP-MS) work?

Answer 6

1. ICP is a torch consisting of a plasma of argon gas that has been ionised using electromagnetic coil.
2. a temp of 6000 to be formed in the torch ionising the sample
3. ion passes through MS and are separated based on their mass to charge ratio

Question 7

What does ICP-MS detect?

Answer 7

mostly metals and several non-metals at very low concentrations

Question 8

what are the challenges faced in micro-mineral studies?

Answer 8

1. elements present but in very low concentrations in the body
   - these technologies are new and people may not have access to detect such low levels
2. no indicators of body status
   - high concentrations can cause toxicity but concentrations in blood may not be indicative of those levels
3. symptoms are usually broad and non-specific and can be difficult to diagnose