Question

Limit test for arsenic is based on _______

• A. \( \text{Gutzeit test} \)
• B. \( \text{Biuret test} \)
• C. \( \text{Black water test} \)
• D. \( \text{Volhard's test} \)

Hint:

Associate the Gutzeit test specifically with the detection and limit testing of arsenic.

Answer 1

The Correct Option is A

The limit test for arsenic, as described in pharmacopoeias, is based on the Gutzeit method. This test involves the generation of arsine gas from any arsenic present in the sample by reaction with zinc and acid. The arsine gas then reacts with mercuric chloride paper, producing a yellow stain. The intensity of this stain is compared with that produced by a standard arsenic solution.