alexa Detection of ultratrace phosphorus and sulfur by quadrupole ICPMS with dynamic reaction cell.
Chemical Engineering

Chemical Engineering

Journal of Analytical & Bioanalytical Techniques

Author(s): Bandura DR, Baranov VI, Tanner SD

Abstract Share this page

Abstract A method of detection of ultratrace phosphorus and sulfur that uses reaction with O2 in a dynamic reaction cell (DRC) to oxidize S+ and P+ to allow their detection as SO+ and PO+ is described. The method reduces the effect of polyatomic isobaric interferences at m/z = 31 and 32 by detecting P+ and S+ as the product oxide ions that are less interfered. Use of an axial field in the DRC improves transmission of the product oxide ions 4-6 times. With no axial field, detection limits (3sigma, 5-s integration) of 0.20 and 0.52 ng/mL, with background equivalent concentrations of 0.53 and 4.8 ng/mL, respectively, are achieved. At an optimum axial field potential (200 V), the detection limits are 0.06 ng/mL for P and 0.2 ng/mL for S, respectively. The method is used for determining the degree of phosphorylation of beta-casein, and regular and dephosphorylated alpha-caseins at 10-1000 fmol/microL concentration, with 5-10\% v/v organic sample matrix (acetonitrile, formic acid, ammonium bicarbonate). The measured degree of phosphorylation for beta-casein (4.9 phosphorus atoms/molecule) and regular alpha-casein (8.8 phoshorus atoms/molecule) are in good agreement with the structural data for the proteins. The P/S ratio for regular alpha-casein (1.58) is in good agreement with the ratio of the number of phosphorylation sites to the number of sulfur-containing amino acid residues cysteine and methionine. The P/S ratio for commercially available dephosphorylated alpha-casein is measured at 0.41 (approximately 26\% residual phosphate).
This article was published in Anal Chem and referenced in Journal of Analytical & Bioanalytical Techniques

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version