Details

Autor(en) / Beteiligte

• Schaumlöffel, Dirk
• Giusti, Pierre
• Preud'Homme, Hugues
• Szpunar, Joanna
• Łobiński, Ryszard

Titel

Precolumn Isotope Dilution Analysis in nanoHPLC−ICPMS for Absolute Quantification of Sulfur-Containing Peptides

Ist Teil von

• Analytical chemistry (Washington), 2007-04, Vol.79 (7), p.2859-2868

Ort / Verlag

Washington, DC: American Chemical Society

Erscheinungsjahr

2007

Quelle

MEDLINE

Beschreibungen/Notizen

• A novel generic approach based on precolumn isotope dilution nanoHPLC−ICPMS analysis was developed for the accurate absolute quantification of sulfur-containing peptides. A 34S-labeled, species-unspecific sulfur spike (sulfate), noninteracting with analyte peptides under the optimized HPLC condition, was added directly to the chromatographic eluents. Thus a generic sulfur standard permanently present during analysis was used for peptide quantification. Interference-free detection of the 32S and 34S isotopes in ICPMS was achieved by eliminating O2 + ions in a collision cell using Xe gas at 130 μL min-1. The detection limit for sulfur was 45 μg L-1 which corresponded to 1−2 pmol of individual peptides. The method was validated by the analysis of a standard peptide solution showing high accuracy (recovery 103%) and good precision (RSD 2.1%). The combination of nanoHPLC−ICP IDMS with nanoHPLC−ESI MS/MS allowed the precise quantification and identification of sulfur-containing peptides in tryptic digests of human serum albumin and salt-induced yeast protein (SIP18) at the picomole level.