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What are common interview questions for freshers applying for Analytical R&Ds in pharmaceutical and food industries?



Hello, everyone. If you have finished your M.Sc. or Ph.D. in Chemistry and looking for a job in Analytical R&Ds of Pharmaceutical industries, you are at the right place.

1. Tell me about yourself.

2. Why do you want this job? Are you willing to relocate?

3. What is the difference between method development and method validation?

4. What is the full form of ICH of which guidelines are widely followed in industries?

5 What is the difference between LoD (Limit of Detection) and LoQ (Limit of Quantification)?

6. What is the difference between GMP (Good Manufacturing Practice) and GLP (Good Laboratory Practice)?

7. What is the difference between a working standard and a reference standard?

8. How to know HPLC column performance? What are theoretical plates?

9. What is the difference between silica used in TLC and HPLC columns?

10. Why do we perform RS (Related Substance) test?

11. Suppose we prepare pH buffer solutions at lab and calibrate them against the NIST solution. Will it be stable in pH and appearance even after 30 days?

12. How to calculate SNR (Signal to noise ratio) in USP and EP (European Pharmacopeia) convention?

13. What is Karl-Fischer titration?

14. What is tailing factor or peak asymmetry factor? How do you calculate resolution and selectivity factor in HPLC? What is fronting and tailing of a peak and how to conclude them?

15. What do you mean by assay? What is API?

16. How will you troubleshoot these RP-HPLC chromatographic issues? - (I) peak is very wide; ii) low detection for peak, (iii) low retention time for peaks, (iv) high peak tailing and splitting of peaks, (v) rounded peaks (vi) unexpected backpressure

17. What is the difference between chromatographic purity and related substances?

18. Which column is having higher resolution - the GC column or the HPLC column?

19. What are the common detectors used in GC (gas chromatography)? Can you tell me the working principles of FID, ECD, NPD, TCD, and MSD?

20. Do you know anything about nitrosamine impurities?

21. What are the leading regulatory agencies of the world in pharmaceutical industries?

22. What is van Beemter equation? What is HETP? What is the relation between resolution and theoretical plates?

23. What is the general chapter number of chromatography?

24. What is the principle of HPLC? Tell me its components. What type of detectors are used in HPLC?

25. What do you mean by gradient and isocratic runs? What is linear gradient run?

26. How do you determine void volumes in HPLC? What is dwell volume?

27. Which chromatographic parameters cannot be adjusted according to the general chapter <621>?

28. Can NMR differentiate a pair of enantiomers? What is the NMR coupling constant?

29. What is the Y-axis in HPLC chromatogram?

30. What are the known ionization sources in LCMS? What are the known mass analyzers in LCMS?

31. What are the common FTR/IR sources?

32. What is paracetamol? Can you give its structure?

33. What is the internal standard used in mass spectrometry? Why is it used so?

34. Name some concentration-dependent and mass flow rate-dependent GC detectors?

35. Why ion-pairing reagents are used in HPLC?

36. Why high pressure is needed in HPLC?

37. When C8 column is preferable to used compared to the C18 column in RP-HPLC?

38. Why widely used solvents like DMF and DMSO are not used in HPLC?

39. How many types of chromatography do you know of?

40. What is the effect on pH with increasing temperature? Does basic pH become acidic and vice versa with the change in temperature?

41. According to you, which solvent should be preferred or would provide better selectivity in RP-HPLC method development? - Acetonitrile (ACN) or MeOH?

42. Why many times columns are washed with IPA (isopropyl alcohol)?

43. How chromatographic purity is determined?

44. How many units after the decimal is used for validation according to the ICH guidelines?

45. What information does van Beemter's plot gives you?

46. In GC, which carrier gas is more preferred and why? Helium or nitrogen?

47. What is the difference in the nature of the stationary phases in GC and HPLC columns?

48. What is called column bleeding?

49. What is the difference between humidity and relative humidity?

50. If you double the HPLC column length, then by how much factor the resolution increases?

51. What are the types of possible contaminants in food items?

52. What are the advantages of UHPLC over HPLC?

53. Which electromagnetic radiation is used in NMR?

54. What is combustion or fuel gas and oxidant gas in GC?

55. How many kinds of capillary GC columns do you know about?

56. What is the difference in ionization sources in GC-MS and LC-MS?

57. What do you know about supercritical fluid chromatography?



Do prepare the answers to these questions. Follow Pharma Growth hub youtube channel and read USP General Chapter <621> and understand before the interview. Google about the products, headquarters, and all other relevant details about the company for which you are sitting in the interview. Read basics about HPLC, GC-MS, LC-MS, NMR, FT-IR instruments and their parts like, columns and detectors commonly used, ionization sources, working principles etc. 



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