May 24, 2024, 03:31:01 PM
Forum Rules: Read This Before Posting


Topic: spectrophotometery  (Read 10810 times)

0 Members and 1 Guest are viewing this topic.

Offline m-khalili

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
spectrophotometery
« on: July 08, 2011, 03:11:47 PM »
hi
I want to know detection of lead ion (Pb2+) in a solution by spectrophotometer without any additive is possible?

Offline Stepan

  • Chemist
  • Full Member
  • *
  • Posts: 358
  • Mole Snacks: +39/-4
  • Gender: Male
  • Air Chemistry Man
    • Supplier of air sampling equipment and services
Re: spectrophotometery
« Reply #1 on: July 08, 2011, 11:21:44 PM »
Lead ion in water is colorless.

Offline m-khalili

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: spectrophotometery
« Reply #2 on: July 09, 2011, 03:29:16 AM »
thanks for your favor
so you mean that for determining the concentration of a metal ion in a solution with spectrophotometer, solution must be colorful?
how about cobalt ?are cobalt salt solution colorful?does the solution color of cobalt salt depend on the PH of solution?
best regard

Offline Stepan

  • Chemist
  • Full Member
  • *
  • Posts: 358
  • Mole Snacks: +39/-4
  • Gender: Male
  • Air Chemistry Man
    • Supplier of air sampling equipment and services
Re: spectrophotometery
« Reply #3 on: July 09, 2011, 07:34:41 AM »
Cobalt ion in water has natural colour and can be detected with spectrofotometer. The colour and its intensity depends on everything: pH, other ions, inorganic impurities (NH3, H2S, Cl,...), some organic impurities (amines, .)

Offline m-khalili

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: spectrophotometery
« Reply #4 on: July 09, 2011, 09:13:18 AM »
thanks so much
may you please help a little more
you mean with out any addition of ligand the concentration of Cobalt can be obtain with spectrophotometer?
 how about using uv visible spectrophotometer for determining  pb2+ or  Hg2+ concentration in the solution (with out addition of any ligend)?
« Last Edit: July 09, 2011, 09:27:51 AM by m-khalili »

Offline BluePill

  • Full Member
  • ****
  • Posts: 100
  • Mole Snacks: +6/-2
  • Gender: Male
  • Difficult is never synonymous to impossible.
Re: spectrophotometery
« Reply #5 on: July 09, 2011, 11:15:10 AM »
Pb2+ and mercury2+ cannot be measured without a ligand with spectrophotometry. You could do AAS if you don't want to use a ligand.

Offline TheUnfocusedOne

  • Full Member
  • ****
  • Posts: 103
  • Mole Snacks: +6/-5
  • Gender: Male
Re: spectrophotometery
« Reply #6 on: July 09, 2011, 12:24:20 PM »
+1 to AAS, probably your best bet.
"Like most heavy metals, thallium is highly toxic and should not be used on breakfast cereal"

Offline m-khalili

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: spectrophotometery
« Reply #7 on: July 09, 2011, 04:23:55 PM »
I havent ASS so i should determine concentration Hg 2+ and Pb2+ by UV VIS spectrophotometer UNICO 2800
can any one suggest some reasonable and availble ligand for determination by this equipment(UV VIS spectrophotometer UNICO 2800_ wavalength range 190_1100 nm and spectral bandwidth of 4nm)?

Offline m-khalili

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: spectrophotometery
« Reply #8 on: July 09, 2011, 05:27:31 PM »
I havent ASS so i should determine concentration of Hg 2+ and Pb2+ by UV VIS spectrophotometer UNICO 2800
can any one suggest some reasonable and availble ligand for determination by this equipment(UV VIS spectrophotometer UNICO 2800_ wavalength range 190_1100 nm and spectral bandwidth of 4nm)?


Offline aeacfm

  • Full Member
  • ****
  • Posts: 226
  • Mole Snacks: +7/-2
  • Gender: Male
Re: spectrophotometery
« Reply #9 on: July 10, 2011, 04:20:31 AM »
i think additives to produce coloure is a must!!!

Offline m-khalili

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: spectrophotometery
« Reply #10 on: July 10, 2011, 04:36:33 AM »
may you please suggest an additive:


Offline m-khalili

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: spectrophotometery
« Reply #12 on: July 10, 2011, 07:27:51 AM »
though  cobalt salt are colorful,but I have read in some paper which researcher have added some additive  for determining cobalt concentration in solution,you think whats the reason?

Offline Stepan

  • Chemist
  • Full Member
  • *
  • Posts: 358
  • Mole Snacks: +39/-4
  • Gender: Male
  • Air Chemistry Man
    • Supplier of air sampling equipment and services
Re: spectrophotometery
« Reply #13 on: July 10, 2011, 08:07:59 AM »
Cobalt and some other ions can be DETECTED in solution without any additional ligands, anions, or reactions. But result is qualitative and usually not sensitive enough.

When you use extra steps of analysis by introducing co-reagents, you increase selectivity, accuracy and sensitivity tremendously.

This is very old area of chemistry developed in 1890-1940's. The methods are well developed. Check the handbooks of analytical chemistry on-line or in your library

Regards

Offline m-khalili

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: spectrophotometery
« Reply #14 on: July 10, 2011, 11:02:13 AM »
tanks
may you please introduce some useful study source for Pb2+ and Hg2+ ligand?

Sponsored Links