AACC AACC Laboratory Instrumentation & Technology

Question 1

Which detector is most commonly used in high-performance liquid chromatography (HPLC) for measuring UV-absorbing analytes in clinical chemistry?

Accepted Answer

UV-Vis spectrophotometric detector

Answer

UV-Vis spectrophotometric detectors are the most widely used in HPLC for clinical analytes that absorb ultraviolet or visible light.

Question 2

What is the primary purpose of an internal standard in mass spectrometry-based clinical assays?

Accepted Answer

To correct for ion suppression and instrument variability

Answer

Internal standards compensate for matrix effects such as ion suppression and variations in instrument response, improving quantitative accuracy.

Question 3

In a clinical chemistry analyzer, what does a reagent blank correct for?

Accepted Answer

Absorbance contributed by the reagent itself

Answer

A reagent blank measures the absorbance of reagents without sample, allowing the analyzer to subtract this background from patient readings.

Question 4

Which ionization technique is considered 'soft' and is commonly used for large biomolecules in clinical mass spectrometry?

Accepted Answer

Electrospray ionization (ESI)

Answer

Electrospray ionization is a soft ionization method that produces intact molecular ions, making it ideal for proteins, peptides, and other large biomolecules.

Question 5

What is carryover in automated clinical analyzers?

Accepted Answer

Contamination of one sample by a preceding high-concentration sample

Answer

Carryover occurs when residual analyte from a high-concentration sample contaminates the subsequent sample, causing falsely elevated results.

AACC - American Association for Clinical Chemistry Certification Practice Test

AACC - American Association for Clinical Chemistry Certification Practice Test

AACC AACC Laboratory Instrumentation & Technology