The authoritative public forum
  for Metal Finishing since 1989
-----

Analytical Method for Phosphorus/Phosphate Detection on Hastelloy Surface?

We're polishing C-276 Hastelloy with a proprietary sulfuric/phosphoric mixture, with which good results are obtained, finish wise. We are experimenting with rinsing and would greatly appreciate comments on the best method(s)to analyze the part surface for presence of residual phosphorous. We have SEM/EDS at our disposal, but large area surveys are like looking for a needle in haystack. Any other suggestions?

Allan Knoll
Process Engineer - Schenectady, New York
November 30, 2010

soak your part in clean di water and then analyze the water for P content using ICP.

Terry Tomt
- Auburn, Washington
December 2, 2010

---

December 8, 2010

Soak the parts (of known surface area) in a 5% sodium carbonate ⇦this on eBay or Amazon] solution to leach out the P on the surface. Test the resulting solution for ortho-phosphate using the single reagent colorimetric (ascorbic acid reduction) method. For details of this last, see "Standard Methods for the Analysis of Water and Wastewater."

Make up the calibration standards in 5% sodium carbonate solution.

Dave Wichern
Consultant - The Bronx, New York