December 05, 2020, 06:36:21 AM
Forum Rules: Read This Before Posting


Topic: Phosphate analysis  (Read 7547 times)

0 Members and 1 Guest are viewing this topic.

bryanh

  • Guest
Phosphate analysis
« on: November 03, 2005, 10:59:25 AM »
Hi
I need to know a good method for organic phosphate analysis. I intend to use this for the detection of the presence of DNA (direct DNA analysis is not possible due to mitigating circumstances). So i need a method that will detect phosphate in the DNA or will decompose DNA to release the phosphate for analysis. I am thinking of molybdenum blue but i'm having trouble finding a procedure that i am sure will be able to detect phosphate in DNA.

Also a simple method for carbon and/or ribose analysis would be great too.
Thanks.

Offline Alberto_Kravina

  • Assault Chemist
  • Retired Staff
  • Full Member
  • *
  • Posts: 608
  • Mole Snacks: +70/-15
Re:Phosphate analysis
« Reply #1 on: November 03, 2005, 11:26:08 AM »
well...the fosfomolibdate test is quite sensitive, other test for fosfate is the MgNH4PO4 precipitation, but I can't think of any other test... ???
« Last Edit: November 03, 2005, 11:26:57 AM by Alberto_Kravina »

Offline Yggdrasil

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 3211
  • Mole Snacks: +482/-21
  • Gender: Male
  • Physical Biochemist
Re:Phosphate analysis
« Reply #2 on: November 04, 2005, 12:32:51 AM »
Is detecting the DNA spectrophotometrically not an option (DNA absorbs UV light at 260nm, 1.0AU ~ 50µg/ml)?

bryanh

  • Guest
Re:Phosphate analysis
« Reply #3 on: November 04, 2005, 04:57:17 AM »
No due to the presence of other chemicals that also absorb at this range UV spec is not a great option.

Offline sdekivit

  • Chemist
  • Full Member
  • *
  • Posts: 403
  • Mole Snacks: +32/-3
  • Gender: Male
  • B.Sc Biomedical Sciences, Utrecht University
Re:Phosphate analysis
« Reply #4 on: November 04, 2005, 04:17:17 PM »
you can determine the purity of your DNA by calculating the A(260) / A(280) - ratio
« Last Edit: November 04, 2005, 04:19:45 PM by sdekivit »

bryanh

  • Guest
Re:Phosphate analysis
« Reply #5 on: November 06, 2005, 10:24:03 AM »
The DNA isn't even in solution, it is (possibly) bound within a large amount of FeS, it requires acid to dissolve the FeS after which no DNA can be detected by UV which is why I am trying to analyse for the constituents of the DNA, phosphate, ribose, etc..  I thought phosphate analysis would be simple, apparently not.

Offline kevins

  • Chemist
  • Full Member
  • *
  • Posts: 176
  • Mole Snacks: +17/-6
  • I'm a llama!
Re:Phosphate analysis
« Reply #6 on: November 09, 2005, 11:08:32 AM »
Please try to digest the sample with acid and then by molybdenum blue. The detection limit can be down to 3 ppb as P.
For Carbon determination, dry the sample first and then determine the carbon by high temperature combustion under oxygen atm and pass thro the gas to soda tube.

Offline Yggdrasil

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 3211
  • Mole Snacks: +482/-21
  • Gender: Male
  • Physical Biochemist
Re:Phosphate analysis
« Reply #7 on: November 10, 2005, 04:06:45 AM »
I recall assaying for free phosphates using ammonium molybdate as a reagent, which allows for colorimetric quantitation of your phosphate concentration.  You can try googling for ammonium molybdate and phosphate assay and see what comes up.

Sponsored Links