Final Master Quiz_Part 2 (41-60)- (HPLC, GC-FID, GC-MS, & FAA)

A set of flashcards covering key concepts and questions related to High-Performance Liquid Chromatography (HPLC) and Flame Atomic Absorption (FAA) techniques to aid in exam preparation.

What parameter affects retention time in HPLC?

A) Polarity of the analyte and mobile phase

What happens if the burner height is too low in FAA?

A) Atom cloud may miss the light beam, reducing absorbance

What happens if you inject too much sample in GC?

B) Peaks become broad and tail

What type of calibration is used when matrix effects are present?

C) Standard addition

What does the detector in GC-FID actually measure?

B) Current generated by ionized carbon species

What does an absorbance of 0.000 mean in FAA?

A) No light absorbed — element not detected

What wavelength is selected in FAA?

B) Specific to the element analyzed (e.g., 324.8 nm for Cu)

In GC-MS, why is a solvent delay used?

B) To avoid contaminating the detector with solvent overload

What is the x-intercept used for in standard addition?

A) It represents the unknown analyte concentration

What is the role of the quadrupole in GC-MS?

B) Filters ions by mass-to-charge ratio

Why must HPLC samples be filtered?

B) To protect the column from particulates

What happens if you forget to blank in FAA or HPLC?

B) Absorbance readings will be offset and inaccurate

What does m/z stand for in GC-MS?

A) Mass-to-charge ratio

What sample property affects separation in GC the most?

C) Boiling point / volatility

Why is methanol mixed with water in HPLC?

A) To adjust mobile phase polarity

What does a high resolution value (Rs) mean in chromatography?

A) Better separation between peaks

What happens to Rs if the flow rate increases in HPLC?

B) Rs decreases — separation gets worse

Which parameter affects LOQ (Limit of Quantitation)?

C) Signal-to-noise ratio

What is the optimal absorbance range for FAA readings?

B) 0.2–1.0

What does the analytical wavelength affect in HPLC or FAA?

B) Sensitivity and selectivity of detection