Atomic absorption spectroscopy

In summary, a 5ml sample diluted to 50ml was measured for absorption, and for several standard solutions. The concentration of iron in the diluted milo drink was found to be 2.57ppm. If you drink 250mL of the undiluted milo drink, then you would consume 2.57g of iron.
  • #1
gordda
20
0
I am having major trouble trying to figure the concentration of a substance that is given by the AAS. Here's the question:
To determine the iron content in a 'Milo' milk drink, a 5ml sample was diluted to 50ml. the absorption of the diluted solution and of several standard solution were measured using AAS.

What mass of iron would you consume by drinking 250ml glass of Milo?

It is given that the concentration of iron, in ppm, in the diluted milo is 2.57ppm hence the concentration of iron, in ppm, in the undiluted milo is 25.7ppm.

If anybody could work this out it would be greatly appreciated

Thanx:)
 
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  • #2
V = 250 mL, C = 25.7 ppm - AAS doesn't mean anything here, you know the volume, you know the concetration, go ahead. The problem is that IMHO the formulation is stupid - ppm is mass of substance per mass of sample but mass of sample is not given. Assume density of water (1 g/mL).
 
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  • #3
but i can't just use the forumla n=cv because i need to change ppm into mol/L. and i have no idea how to do that? how do u change ppm into mol/L.
 
  • #4
google: ppm concentration
 
  • #5
gordda said:
but i can't just use the forumla n=cv because i need to change ppm into mol/L. and i have no idea how to do that? how do u change ppm into mol/L.
Follow Borek's advice. Assume that milk has the density of water.

1 ppm means there's 1 gm of Fe in a million gms of milk. Convert the first number into moles (from the atomic wt of Fe) and the second into a volume (assuming the density as above), and you are done.
 
  • #6
There is no need for any conversions! You are asked about mass of iron so you don't need molar concentration for anything.
 
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  • #7
Borek said:
There is no need for any conversions! You are asked about mass of iron so you don't need molar concentration for anything.
Ummm...yes; didn't look carefully. Still need to convert volume of solution into a mass, but that's the only one.
 

Related to Atomic absorption spectroscopy

What is atomic absorption spectroscopy?

Atomic absorption spectroscopy is a technique used to analyze the concentration of elements in a sample by measuring the amount of light absorbed by atoms of those elements. This is achieved by exposing the sample to a beam of light with a specific wavelength and then measuring the intensity of light after it passes through the sample.

How does atomic absorption spectroscopy work?

In atomic absorption spectroscopy, a source of electromagnetic radiation is used to excite the atoms in the sample. As the atoms absorb the energy from the light, they move to higher energy levels. When the atoms return to their ground state, they emit light at specific wavelengths, which can be measured to determine the concentration of the element in the sample.

What are the advantages of atomic absorption spectroscopy?

Atomic absorption spectroscopy is a highly sensitive and specific technique, meaning it can detect even trace amounts of elements in a sample. It is also a relatively simple and fast method, making it suitable for routine analysis in laboratories. Additionally, it is non-destructive, meaning the sample can be reused for further analysis.

What are the limitations of atomic absorption spectroscopy?

One limitation of atomic absorption spectroscopy is that it can only analyze one element at a time. This means that multiple samples or instruments are needed for analyzing different elements. Additionally, it requires a pure and homogenous sample, as impurities or variations in the sample's composition can affect the accuracy of the results.

What are the applications of atomic absorption spectroscopy?

Atomic absorption spectroscopy has a wide range of applications in various fields such as environmental monitoring, pharmaceuticals, and food and beverage analysis. It is commonly used to analyze the concentration of metals in water, soil, and biological samples. It is also used in quality control and research and development in industries such as mining and agriculture.

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