Ion-pair reversed-phase chromatography for speciation of organotin compounds

Abstract

Objective: Ion-pair reversed-phase chromatography (IP-RP) has been investigated for speciation of dibutyltin (DBT), tributyltin (TBT), and triphenyltin (TPhT). The influence of several parameters (pH, alkyl chain length, concentration of the ion pair reagent) has been studied to determine the best chromatographic conditions. Methods: Separation of the three organotin compounds was achieved on a C8-bonded silica column using a mixture of methanol, water, and acetic acid (80:19:1) as eluent, containing 1 mmol/L decane sulfonic acid as ion pairing reagent. The eluates were detected on-line by hydride generation-quartz furnace atomic absorption spectrophotometry (HG-QFAAS). Results: The resolving power of this developed method for separation of the organotins species at above conditions was shown by the values of fundamental chromatographic parameters. The capacity factors (k’) for DBT, TBT and TPhT species were 0.27, 2.54, and 5.92 respectively. Resolution (Rs) values for DBT-TBT and TBT-TPhT separation were 2.92 and 2.42 respectively, while the selectivity for DBT-TBT and TBT-TPhT were 9.76 and 3.50 respectively. Conclusion: The developed IP-RP-HG-QFAAS chromatography technique can separate DBT, TBT, and TPhT with good performance which is shown by the chromatographic parameters produced.