Ion-pair chromatography of bis (sodium-sulfopropyl) disulfide brightener in acidic copper plating baths.
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.
Palmans
Roger
R
IMEC, Kapeldreef 75, B-3001 Leuven, Belgium. palmans@imec.be
Claes
S
S
Vanatta
L E
LE
Coleman
D E
DE
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
D004220:Disulfides; D003300:Copper