The Method of Testing The Presence Of Arsenic

1. Destination laboratory

2. Learning The Method of Testing The Presence Of Arsenic

3. ANALYSIS OF WATER Portable kit is used: Sample: fresh water body….(stagnant water) pH-6.5-8.5 , conductivity-553uS/cm, Salinity- 0 Dissolved Oxygen- > 4

4. Ion Selective Electrode (ISE):

5. Ion selective Electrode Probe for fluoride ion detection- 10 ml of sample is taken. Lanthanum crystal electrode used …. TISAB( Total Ionising Strength Adjustable Buffer) is used Result- F -1 present – 0.379 mg/l

6. ARSENIC DETECTION Procedure- KI is added to sample of contaminated water- colour changes from colourless to purple. Zn added --- changes arsenic from pentavalent to trivalent Compound of Zinc added ----- colour changes to grey Mercuric chloride paper held above but the solution must not touch it If arsine gas come in contact with the paper gas turns to mercuric arsenate after 20 min black colour would be seen. Experiment performed by the students in the chemistry laboratory at Geological Survey of India(GSI)

7. B lack colouration here indicates that the sample contains arsenic. Arsenic test kit

8. Handling the portable kit probe

9. Total hardness: Ca and Mg ions contribute to hardness

10. Total Hardness Titration Method :- In burette EDTA is taken The sample is taken in dish. 2 drops of EBT indicator is added….Buffer is mixed…………… Observation- colour changes from pink to blue . Hence Mg +2 and Ca +2 are present …..

11. Thank you… By B.D.M.International