Organotin speciation via HPLC-ICP-MS

Suyani and co-workers [76] have used ICP-MS for the detection of several organotin compounds separated by HPLC. Both ion exchange and ion pairing chromatography were investigated. Sub-ng limits of detection were obtained and compared with ICP-AES detection. ICP-MS was found to be three orders of magnitude more sensitive than ICP-AES. 

The interface between the chromatograph and ICP-MS consisted of a 40 cm length of 0.25 mm i.d. Teflon tubing connecting the end of the HPLC column to a Hildebrand grid nebulizer. A Scott-type double pass spray chamber was cooled to -8° C in order to minimize the amount of solvent vapor reaching the plasma. 

A strong cation exchange stationary phase was used with a mobile phase consisting of 0.1 M ammonium acetate in 85% v/v methanol/water. 

The flow rate was 1 ml min The ion pairing work involved a Cig column and mobile phase of 4 mM sodium pentane sulfonate in a mixture of 80 19 1 methanol/water/acetic acid. The pH was adjusted to 3.00 with the addition of 1 M sulfuric acid. A typical ion exchange chromatogram is shown in Fig. 3.3. 

Recently, Suyani and co-workers [77] have investigated the use of micellar liquid chromatography (MLC), as an alternative to to the methods given above, with ICP-MS detection. The organic solvents commonly used in HPLC mobile phases can decrease sensitivity due to excessive 

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