Question 1

Which of the following chemical tests is the best first screening test for drugs?&#10;A) Marquis&#10;B) Chen's&#10;C) Duquenois-Levine&#10;D) Zimmerman's

Accepted Answer

The Marquis reagent test is the best first screening test for drugs because it is a general test that can quickly identify multiple classes of drugs, including opioids, amphetamines, and hallucinogens. The other tests listed may have a more specific detection ability, but they are not as effective for initial screening purposes.

Question 2

The Duquenois-Levine test is a screening test for _____.&#10;A) heroin&#10;B) marijuana&#10;C) cocaine&#10;D) psilocin&#10;E) caffeine

Accepted Answer

The Duquenois-Levine test is specifically used for the detection of marijuana in a sample. It involves adding a mixture of vanillin and ethanol to the sample and observing any color changes that occur.

Question 3

____ tests identify drugs by the size and shape of their crystals formed when the drug is mixed with specific reagents.&#10;A) HPLC&#10;B) color&#10;C) TLC&#10;D) microcrystalline

Accepted Answer

Microcrystalline tests involve mixing the drug with specific reagents, then observing the size and shape of the resulting crystals under a microscope. This method can be used to identify certain drugs based on their characteristic crystal formations. HPLC and TLC are chromatography techniques used to separate and analyze drug compounds, while color tests rely on color changes to indicate the presence of specific drugs but do not identify them based on crystal formation.

Question 4

Which of the following chemical tests is a screening test for cocaine?&#10;A) Marquis&#10;B) Scott's&#10;C) Duquenois-Levine&#10;D) Van Urk's

Accepted Answer

Scott's test is a colorimetric test specifically used as a presumptive screening test for cocaine. It involves adding a sample to a mixture of chemicals, resulting in a color change that indicates the presence of cocaine.

Question 5

A white precipitate is a positive result with this test used to detect the presence of alkaloids.&#10;A) Dillie-Koppanyi&#10;B) Scott&#10;C) Duquenois-Levine&#10;D) Marquis&#10;E) Mayer's

Accepted Answer

Mayer's reagent is used to detect the presence of alkaloids and a white precipitate is a positive result. The other reagents listed may also be used in drug testing but do not produce a white precipitate with alkaloids.

Question 6

Why would an investigator NOT use color tests at a crime scene?

Accepted Answer

The answer of Why would an investigator NOT use color...

Question 7

Chemically, how does the Mecke test work? Be specific using morphine as your example.

Accepted Answer

The answer of Chemically, how does the Mecke test work?...

Question 8

Chemically, how does the ferric chloride test work? Be specific using salicylates acid as your example.

Accepted Answer

The answer of Chemically, how does the ferric chloride test...

Question 9

Chemically, how does the Chen test work? Be specific using ephedrine as your example.

Accepted Answer

The answer of Chemically, how does the Chen test work?...

Question 10

Explain how the incidence of fentanyl and carfentanil cases has altered drug testing approaches.

Accepted Answer

The answer of Explain how the incidence of fentanyl and...

Deck 2: Chemical Tests