10 Interview questions in Atomic Absorption Spectroscopy

In this module I have posed before you some typical questions which you could come across during interview sessions when you apply for a job involving use of atomic absorption spectrometers. I have deliberately not provided you with tailored made answers and the objective is to motivate you to look for the answers. I’m sure that if you review the earlier modules on the topic you’ll find all your answers. This exercise will encourage you to search for solutions that you are faced with not only in atomic absorption spectroscopy but in other areas of your activity as well. I request all to look for answers and in case you wish to have some clarifications or share your views you are welcome to participate in discussion forums so that other readers also get the benefit..

Q1. Explain briefly the principle of operation of an Atomic Absorption Spectrometer?

Q2. What is the difference in operation principle of AAS and AES?

Q3. Why is nitrous oxide used as oxidant in some applications?

Q4. What are the advantages of using Electrodeless discharge lamps over Hollow cathode lamps as light sources for analysing some elements?

Q5. What are the advantages of double beam over single beam operation?

Q6. What is the role of a flow spoiler or an impact bead in the spray chamber? Explain the benefits of each over the other.

Q7. What is the role of a monochromator in the atomic absorption spectrometer?

Q8. What do you understand by deuterium background correction and what are its limitations?

Q9. Explain the benefits of graphite furnace analysis over flame analysis?

Q10. What are the limitations in analysis of analysis of volatile elements such as As, Sn, Pb,Sb ,etc What alternate sample treatment option is commonly used for such analysis?

Wishing you good luck for your future pursuits and looking forward to our long time association.

About Dr. Deepak Bhanot

Dr Deepak Bhanot is a seasoned professional having nearly 30 years expertise beginning from sales and product support of analytical instruments. After completing his graduation and post graduation from Delhi University and IIT Delhi he went on to Loughborough University of Technology, UK for doctorate research in analytical chemistry. His mission is to develop training programs on analytical techniques and share his experiences with broad spectrum of users ranging from professionals engaged in analytical development and research as well as young enthusiasts fresh from academics who wish to embark upon a career in analytical industry.

Comments

  1. Background correction in atomic absorption spectroscopy technique which is no suitable for alkali metals?
    1-Zyman
    2-Two lines
    3-Smith – Hyfjh
    4-Continuous source

    • Hi Javad,
      Common background correction used for majority of applications is Continuum Deuterium lamp in the flame mode.Alkali metals can also be analysed using this background correction mode. Zeeman correction is the other correction option that is commonly used when using graphite furnace with more complex matrices.

  2. Abdalla Mohammed says:

    What is the role of a flow spoiler or an impact bead in the spray chamber? Explain the benefits of each over the other.

    • Hi Abdalla,
      Role of flow spoiler or impact bead is to remove large size liquid droplets reaching the spray chamber so that only droplets of a defined size can enter the flame.large droplets are deflected from the incoming gas stream and are drained out.One can choose from either a flow spoiler or an impact bead.Bead removes fewer large droplets and results in higher sensitivity as more sample reaches the flame However, large droplets lead to decreased precision and more interferences.Glass or ceramic beads can also lead to more contamination and memory effects.Flow spoiler which is made from inert material contributes less to such interferences but often gives lower sensitivity.

  3. Rose Elaine E. Placio says:

    Hello!
    Am currently analyzing lead contents of commonly consumed processed foods in the Philippines using GF-AAS. I wish to seek some advice regarding the problems I’ve been encountering in my analysis. Recently, the absorbance of my samples lowered more than half compared to my previous readings. I’ve read the same samples I’ve analyzed before and the absorbance was really reduced to half of its initial reading. Have checked the lamp but it is still in good condition. line search appears ok, too. Can anybody please help. Thank youuuuuu!

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