What is the rapid screening method for trace elements?

• A. Reinsch Test
• B. Marsh Test
• C. Diphenylcarbazide Test
• D. Kjeldahl Method

Answer: (A)

The rapid screening for trace elements is done with the Reinsch test. In this method, a clean copper strip is placed in an acidified sample so that metal ions in the solution can be deposited onto the copper surface. If trace metals are present, they reduce and form a thin metallic film on the strip, producing a visible coating that serves as a quick qualitative indication of metals in the sample. This makes it a fast first screen for various metals before moving on to more precise tests. The other options are more specific or different in purpose: the Marsh test targets arsenic by generating arsine gas; the diphenylcarbazide test detects chromium(VI) colorimetrically; and the Kjeldahl method measures nitrogen content, not metals.