title: Ion-pair chromatography of bis (sodium-sulfopropyl) disulfide brightener in acidic copper plating baths.
abstract: Quantitative analysis of the brightener component bis (sodium-sulfopropyl) disulfide (SPS) in acidic copper plating baths poses a real challenge due to the complex chemical matrix containing large amounts of Cu(II) ion and sulfuric acid together with other organic additives and additive decomposition products. We developed a new ion-pair chromatography method to analyze micro-molar amounts of SPS directly in plating bath samples without the need for sample pre-treatment. Addition of tetra-N-methylammonium cation as ion-pairing agent to a methanol-sulfuric acid-water eluent increases the retention time of the anionic SPS2- on a C18 column sufficiently to separate this compound from Cu(II) ion and additive by-products.
authors.affiliation: IMEC, Kapeldreef 75, B-3001 Leuven, Belgium. palmans@imec.be
authors.forename: Roger
authors.initials: R
authors.lastname: Palmans
authors.forename: S
authors.initials: S
authors.lastname: Claes
authors.forename: L E
authors.initials: LE
authors.lastname: Vanatta
authors.forename: D E
authors.initials: DE
authors.lastname: Coleman
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002852:Chromatography, Ion Exchange / Q000379:methods*; D003300:Copper / Q000737:chemistry*; D004220:Disulfides / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015203:Reproducibility of Results
chemical_list: D004220:Disulfides; D003300:Copper