The document describes the procedure for conducting an arsenic limit test using a Gutzeit apparatus. The test works by generating arsine gas from a sample using zinc and hydrochloric acid, which then reacts with mercuric chloride in the apparatus to form a yellow stain on filter paper that can be compared to a standard. If the stain produced by the sample is no deeper than the standard stain after 40 minutes, then the sample passes the limit test for arsenic concentration.

1. LIMIT TEST FOR ARSENIC
Presented By,
Ms. Kiran Ravindra Divekar
Assistant Professor, SCPER, Kopargaon

2. “
Apparatus used for Arsenic limit test

3. “ ‘Gutzeit
Apparatus’

4. PRINCIPLE
HgCl2 + 2AsH3 Hg(AsH2)2 + 2HCl
As H3AsO3
Zn + HCl
(Nascent Hydrogen)
AsH3
Mercuric chloride
Hg(AsH2)2 + 2HCl
(Arsenic) (arsenious acid) (arsine gas) (Mercuric arsenide)
Stannated acid
Stannated acid: HCl + stannus chloride in minimum quantity

5. “
PROCEDURE

6. “
If the stain produced by test is no deeper than
standard stain, then sample complies limit test
for arsenic.
OBSERVATION

7. “
After 40 minutes, if the intensity of the
yellow stain produced in the standard is
more that in the test, the sample complies
with the limit test of lead.
RESULT & CONCLUSION

8. “THANK
YOU”