Simultaneous Determination of Palladium and Platinum by On-line Enrichment and HPLC with 4-(2-Hydroxynaphthalene- 1-ylmethylene)-thiazolidine-2,5-Dithione as Pre-column Derivatization Reagent

  • H Yin
  • Q Hu
  • Q Lin
  • Z Huang
  • G Yang
Keywords: Palladium, platinum, 4-(2-hydroxy-naphthalene-1-ylmethylene)-thiazolidine-2, 5-dithione, high performance liquid chromatography, on-line enrichment.


In this paper, a new reagent, 4-(2-hydroxy-naphthalene-1-ylmethylene)-thiazolidine-2,5-dithione (HNMTD) was synthesized. A new method for the simultaneous determination of palladium and platinum ions as metal-HNMTD chelates was developed using high performance liquid chromatography equipped with an on-line enrichment technique. Prior to chromatography the palladium and platinum ions were derivatized with HNMTD to coloured chelate complexes. The Pd-HNMTD and Pt-HNMTD complexes were then enriched on an enrichment column(ZORBAXReversed Phase StableBoundC18, 4.6×10mm,1.8 μm) using a buffer solution of 0.05 mol L–1 sodium acetate-acetic acid buffer (pH 3.8) as mobile phase.After the enrichment was completed, the retained chelates were back-flushed to the analytical column. The separation of chelates on the analytical column (ZORBAX Reversed Phase Stable Bound C18, 4.6 × 50 mm, 1.8 μm) was satisfactory when 72% methanol (containing 0.05 mol L–1 of pH 3.8 sodium acetate-acetic acid buffer salt and 0.1% of TritonX-100) was used as mobile phase. The Pt-HNMTD and Pd-HNMTD chelates were separated completely within 2 min. The detection limits (S/N = 3) for palladium and platinum were 1.2 ng L–1 and 1.4 ng L–1, respectively. The method was applied with good results to the determination of palladium and platinum in water and urine samples.

Keywords: Palladium, platinum, 4-(2-hydroxy-naphthalene-1-ylmethylene)-thiazolidine-2,5-dithione, high performance liquid chromatography, on-line enrichment.


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eISSN: 0379-4350