Analytical techniques (chromatography, spectroscopy) MCQs Food science December 27, 2025August 5, 2024 by u930973931_answers 50 min Score: 0 Attempted: 0/50 Subscribe 1. . What does chromatography primarily separate? (A) Mixtures into individual components (B) Solids from liquids (C) Gases into different phases (D) Nutrients from non-nutrients 2. . Which of the following is a type of chromatography where the stationary phase is a liquid coated on a solid support? (A) Thin-layer chromatography (B) Liquid chromatography (C) Gas chromatography (D) High-performance liquid chromatography 3. . In gas chromatography (GC), what is typically used as the mobile phase? (A) Liquid solvent (B) Gas (C) Solid support (D) Gel 4. . Which type of chromatography uses a liquid mobile phase and a solid stationary phase? (A) Gas chromatography (B) Supercritical fluid chromatography (C) Liquid chromatography (D) Thin-layer chromatography 5. . What is the primary purpose of using a detector in chromatography? (A) To separate the components (B) To identify and quantify the separated components (C) To prepare the sample (D) To enhance the separation efficiency 6. . What does the term “retention time” refer to in chromatography? (A) The time required for the detector to analyze the compound (B) The time taken to prepare the sample (C) The time a compound takes to pass through the chromatographic system (D) The duration of the experiment 7. . Which type of chromatography is commonly used for separating complex mixtures in food science? (A) Gas chromatography (B) Paper chromatography (C) Liquid chromatography (D) Column chromatography 8. . In high-performance liquid chromatography (HPLC), what is the role of the pump? (A) To separate the sample components (B) To move the mobile phase through the chromatographic column (C) To detect the components (D) To prepare the sample 9. . Which type of detector in HPLC is based on measuring UV light absorption? (A) Refractive index detector (B) Fluorescence detector (C) UV-Vis detector (D) Conductivity detector 10. . What is the main principle of mass spectrometry (MS)? (A) To measure the mass-to-charge ratio of ions (B) To separate components based on their size (C) To measure the light absorption of compounds (D) To detect changes in the compound’s viscosity 11. . Which technique combines chromatography with mass spectrometry for detailed analysis of compounds? (A) Liquid chromatography-mass spectrometry (LC-MS) (B) Gas chromatography-mass spectrometry (GC-MS) (C) Thin-layer chromatography-mass spectrometry (TLC-MS) (D) High-performance liquid chromatography-mass spectrometry (HPLC-MS) 12. . What does “spectroscopy” measure in analytical techniques? (A) The mass of ions (B) Separation of components (C) Interaction of light with matter (D) The viscosity of a sample 13. . Which type of spectroscopy is used to identify functional groups in organic compounds? (A) Mass spectrometry (MS) (B) Ultraviolet-visible (UV-Vis) spectroscopy (C) Nuclear magnetic resonance (NMR) spectroscopy (D) Infrared (IR) spectroscopy 14. . What is the primary use of ultraviolet-visible (UV-Vis) spectroscopy in food science? (A) To measure the mass of food particles (B) To separate different food components (C) To determine the concentration of compounds based on their light absorption (D) To analyze the viscosity of food products 15. . Which type of spectroscopy provides information about the molecular structure of compounds by analyzing their magnetic properties? (A) Mass spectrometry (MS) (B) Infrared (IR) spectroscopy (C) Ultraviolet-visible (UV-Vis) spectroscopy (D) Nuclear magnetic resonance (NMR) spectroscopy 16. . What does the “chromatographic peak area” in a chromatogram indicate? (A) The purity of the compound (B) The time taken for the compound to elute (C) The quantity of the compound present in the sample (D) The interaction of the compound with the stationary phase 17. . Which type of chromatography is best suited for separating gases? (A) Gas chromatography (B) Liquid chromatography (C) Thin-layer chromatography (D) Column chromatography 18. . What is the main advantage of using liquid chromatography (LC) over other chromatography techniques? (A) It requires less sample preparation (B) It is faster than gas chromatography (C) It can separate a wide range of compounds with high resolution (D) It is less expensive than other techniques 19. . Which of the following detectors in GC measures compounds based on their thermal conductivity? (A) Mass spectrometer (MS) (B) Flame ionization detector (FID) (C) Electron capture detector (ECD) (D) Thermal conductivity detector (TCD) 20. . In UV-Vis spectroscopy, what does the absorbance value represent? (A) The amount of light transmitted through the sample (B) The amount of light absorbed by the sample (C) The sample’s refractive index (D) The temperature of the sample 21. . What is the role of the stationary phase in chromatography? (A) To move the mobile phase through the column (B) To separate the sample components based on their interactions (C) To detect the separated components (D) To prepare the sample for analysis 22. . Which technique uses a silica gel or alumina plate as the stationary phase? (A) Supercritical fluid chromatography (SFC) (B) Gas chromatography (GC) (C) High-performance liquid chromatography (HPLC) (D) Thin-layer chromatography (TLC) 23. . What is the primary purpose of using a column in chromatography? (A) To enhance the sensitivity of the detector (B) To prepare the sample for analysis (C) To separate the different components of the sample (D) To stabilize the mobile phase 24. . Which technique is best for detecting trace amounts of compounds in complex mixtures? (A) Infrared (IR) spectroscopy (B) Ultraviolet-visible (UV-Vis) spectroscopy (C) Mass spectrometry (MS) (D) Nuclear magnetic resonance (NMR) spectroscopy 25. . What is “resolution” in the context of chromatography? (A) The ability to distinguish between two closely spaced peaks (B) The speed of the chromatographic process (C) The amount of sample required (D) The sensitivity of the detector 26. . Which type of chromatography is used for separating proteins and peptides? (A) Thin-layer chromatography (TLC) (B) Gas chromatography (GC) (C) High-performance liquid chromatography (HPLC) (D) Supercritical fluid chromatography (SFC) 27. . In NMR spectroscopy, what information does the chemical shift provide? (A) The wavelength of absorbed light (B) The mass of the sample (C) The environment of specific nuclei in the molecule (D) The concentration of the compound 28. . Which of the following is a key feature of high-performance liquid chromatography (HPLC)? (A) Low cost of equipment (B) High resolution and sensitivity for analyzing compounds (C) Ability to analyze only gases (D) Use of a solid stationary phase only 29. . What is the purpose of a calibration curve in spectroscopy? (A) To separate different components in a mixture (B) To determine the concentration of unknown samples based on their absorbance (C) To adjust the temperature during analysis (D) To enhance the resolution of the chromatographic peaks 30. . Which type of detector in HPLC is used for detecting compounds that do not absorb UV light? (A) Refractive index detector (RID) (B) UV-Vis detector (C) Fluorescence detector (D) Conductivity detector 31. . In gas chromatography, what is the purpose of the injector? (A) To move the mobile phase (B) To separate the components (C) To detect the components (D) To introduce the sample into the chromatographic column 32. . Which type of spectroscopy provides information about the molecular vibrations and rotations of a compound? (A) Ultraviolet-visible (UV-Vis) spectroscopy (B) Infrared (IR) spectroscopy (C) Nuclear magnetic resonance (NMR) spectroscopy (D) Mass spectrometry (MS) 33. . Which detector in GC is used to measure compounds that are not easily ionized? (A) Thermal conductivity detector (TCD) (B) Flame ionization detector (FID) (C) Electron capture detector (ECD) (D) Mass spectrometer (MS) 34. . What is the primary benefit of using supercritical fluid chromatography (SFC)? (A) It is less expensive than other chromatography techniques (B) It combines properties of both gases and liquids, offering high efficiency and resolution (C) It requires no sample preparation (D) It is limited to only non-polar compounds 35. . What does “peak area” in chromatography represent? (A) The temperature of the sample (B) The time taken for the compound to elute (C) The quantity of a particular compound in the sample (D) The interaction of the compound with the stationary phase 36. . Which type of NMR spectroscopy provides information about the molecular dynamics and flexibility of compounds? (A) Solid-state NMR (B) Multi-dimensional NMR (C) High-resolution NMR (D) Solution-state NMR 37. . Which of the following is an advantage of using UV-Vis spectroscopy? (A) It is quick and requires minimal sample preparation (B) It provides detailed structural information (C) It can detect compounds at very low concentrations (D) It separates complex mixtures 38. . What is the function of the mobile phase in chromatography? (A) To prepare the sample for analysis (B) To separate the sample components (C) To detect the separated components (D) To carry the sample through the stationary phase 39. . Which chromatography technique is most suitable for analyzing volatile compounds? (A) Thin-layer chromatography (TLC) (B) Liquid chromatography (LC) (C) Gas chromatography (GC) (D) High-performance liquid chromatography (HPLC) 40. . In chromatography, what does “selectivity” refer to? (A) The time taken for the analysis (B) The amount of sample required (C) The ability of the stationary phase to differentiate between different compounds (D) The type of detector used 41. . Which type of spectroscopy can provide information about the electronic structure of a molecule? (A) Mass spectrometry (MS) (B) Infrared (IR) spectroscopy (C) Nuclear magnetic resonance (NMR) spectroscopy (D) Ultraviolet-visible (UV-Vis) spectroscopy 42. . What does “peak height” in a chromatogram typically indicate? (A) The purity of the compound (B) The time required for elution (C) The temperature of the column (D) The concentration of a compound in the sample 43. . Which technique uses a mobile phase that is supercritical fluid? (A) Supercritical fluid chromatography (SFC) (B) Gas chromatography (GC) (C) Liquid chromatography (LC) (D) Thin-layer chromatography (TLC) 44. . In mass spectrometry, what does “molecular ion peak” represent? (A) The peak indicating the presence of impurities (B) The peak corresponding to fragmented ions (C) The peak indicating the presence of a solvent (D) The peak corresponding to the molecule with its original mass-to-charge ratio 45. . Which detector in HPLC is used for compounds that exhibit fluorescence? (A) Refractive index detector (B) UV-Vis detector (C) Fluorescence detector (D) Conductivity detector 46. . What is the primary purpose of using a gradient elution in HPLC? (A) To increase the sample preparation time (B) To improve separation efficiency by gradually changing the mobile phase composition (C) To reduce the analysis time (D) To enhance the sensitivity of the detector 47. . In IR spectroscopy, which region is typically used to identify functional groups? (A) Absorption region (B) High-wavenumber region (C) Low-wavenumber region (D) Fingerprint region 48. . What does “chromatographic resolution” measure? (A) The ability to distinguish between two closely spaced peaks in a chromatogram (B) The overall analysis time (C) The amount of sample required (D) The sensitivity of the detector 49. . Which chromatography technique is known for its high sensitivity and resolution? (A) Supercritical fluid chromatography (SFC) (B) Gas chromatography (GC) (C) Thin-layer chromatography (TLC) (D) High-performance liquid chromatography (HPLC) 50. . In UV-Vis spectroscopy, what does a higher absorbance value indicate? (A) A shorter wavelength of the absorbed light (B) A lower concentration of the absorbing species in the sample (C) A lower molecular weight of the absorbing species (D) A higher concentration of the absorbing species in the sample