Toxicology (Chemistry)

Question 1

Which of the following elevates carboxyhemoglobin?

A) nitrite poisoning
B) exposure to carbon monoxide
C) sulfa drug toxicity
D) sickle cell anemia

Answer 1

B) exposure to carbon monoxide

Question 2

The reason carbon monoxide is so toxic is because it:

A) is a protoplasmic poison
B) combines with cytochrome oxidase
C) has 200 times the affinity of oxygen for hemoglobin binding sites
D) sensitizes the myocardium

Answer 2

C) has 200 times the affinity of oxygen for hemoglobin binding sites

Question 3

Cocaine is metabolized to:

A) carbamazepine
B) codeine
C) hydrocodone
D) benzoylecgonine

Answer 3

D) benzoylecgonine

Question 4

The metabolite 11-nor-tetrahydrocannabinol-9-COOH can be detected by immunoassay 3-5 days after a single use of:

A) methamphetamine
B) cocaine
C) benzodiazepine
D) marijuana

Answer 4

D) marijuana

Question 5

A 3-year old child was evaluated for abdominal pain and anorexia by a physician. A CBC revealed a hemoglobin of 9.8 g/dL (98 g/L) and basophilic stippling of the RBCs. The doctor should order further tests to check for poisoning from:

A) arsenic
B) iron
C) mercury
D) lead

Answer 5

D) lead

Question 6

Zinc protoporphyrin or free erythrocyte protoporphyrin measurements are useful to assess blood concentrations of:

A) lead
B) mercury
C) arsenic
D) beryllium

Answer 6

A) lead

Question 7

A salicylate level is performed to detect toxicity caused by ingestion of excess:

A) acetaminophen
B) aspirin
C) ibuprofen
D)pseudoephedrine

Answer 7

B) aspirin

Question 8

Testing for the diagnosis of lead poisoning in children should include:

A) erythrocyte protoporphyrin (EPP)
B) urine delta-aminolevulinic acid
C) whole blood lead
D) zinc protoporphyrin (ZPP)

Answer 8

C) whole blood lead

Question 9

Upon development of a thin-layer chromatogram for drug analysis all drug spots (including the standards) had migrated with the solvent front. The most probable cause for this would be:

A) environmental temperature too warm
B) incorrect aqueous to nonaqueous solvent mixture
C) too much sample applied
D) chromatogram dried too quickly

Answer 9

B) incorrect aqueous to nonaqueous solvent mixture

Question 10

To detect barbiturate abuse when analyzing urine specimens, immunoassay is the method of choice for screening. The method of choice for confirmation is:

A) nephelometry
B) thin-layer chromatography
C) gas chromatography/mass spectrometry
D) ultraviolet absorption spectroscopy

Answer 10

C) gas chromatography/mass spectrometry