ETC Laboratory Analysis & Forensic Science Flashcards

Which type of analysis uses ninhydrin reagent to develop latent fingerprints on porous surfaces such as paper?

Answer: Amino acid-based chemical development

Ninhydrin reacts with amino acids left by skin oils to develop purple-colored latent prints on porous surfaces like paper.

What is the purpose of a control sample in forensic laboratory analysis?

Answer: To establish a baseline for comparison and validate test results

A control sample provides a known baseline so analysts can confirm the test is performing correctly and results are valid.

Which analytical technique is considered the gold standard for identifying and quantifying drugs in seized samples?

Answer: Gas chromatography-mass spectrometry (GC-MS)

GC-MS separates compounds by gas chromatography then identifies them by mass spectrometry, providing highly accurate drug identification.

An evidence technician submits a white powder to the lab. Which presumptive test would indicate the possible presence of cocaine?

Answer: Scott test (cobalt thiocyanate)

The Scott test produces a blue color in the presence of cocaine, serving as a presumptive indicator before confirmatory analysis.

What does a forensic toxicology report primarily establish in a criminal investigation?

Answer: The presence, identity, and concentration of substances in biological specimens

Forensic toxicology analyzes biological specimens such as blood and urine to detect, identify, and quantify drugs, alcohol, and poisons.

When submitting biological evidence to a forensic lab, which packaging material is preferred over plastic bags?

Answer: Paper bags or paper envelopes

Paper packaging allows moisture to escape, preventing mold and bacterial growth that would degrade DNA and other biological evidence.