Speciation of butyl- and phenyltin compounds in sediments using pressurized liquid extraction and liquid chromatography-inductively coupled plasma mass spectrometry.
A liquid chromatographic method with inductively coupled plasma mass spectrometry is proposed for the speciation of butyl- (monobutyltin, dibutyltin, tributyltin) and phenyl- (monophenyltin, diphenyltin, triphenyltin) tin compounds in sediments. After evaluation of different additives in the mobile phase, the use of 0.075% (w/v) of tropolone and 0.1% (v/v) of triethylamine in a mobile phase of methanol-acetic acid-water (72.5:6:21.5) allowed the best chromatographic separation of the six compounds. Pressurized liquid extraction (PLE) with a methanolic mixture of 0.5 M acetic acid and 0.2% (w/v) of tropolone was suitable for the quantitative extraction of butyl- and phenyltin compounds with recovery values ranging from 72 to 102%. This analytical approach was compared to conventional solvent extraction methods making use of acids and/or organic solvent of medium polarity. The main advantages of PLE over conventional solvent extraction are: (i) the possibility to extract quantitatively DPhT and MPhT from sediments, which could not be done by a solvent extraction approach; (ii) to preserve the structural integrity of the organotin compounds; (iii) to reduce the extraction time from several hours in case of solvent extraction techniques to just 30 min. For spiked sediments, limits of detection ranged from 0.7 to 2 ng/g of tin according to the compound. The relative standard deviations were found to be between 8 and 15%. The developed analytical procedure was validated using a reference material and was applied to various environmental samples.
Chiron
S
S
BRGM, Service Analyse et Caractérisation Minérale, Orléans, France. s.chiron@brgm.fr
Roy
S
S
Cottier
R
R
Jeannot
R
R
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D009947:Organotin Compounds / Q000737:chemistry*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012989:Soil Pollutants / Q000032:analysis*
D009947:Organotin Compounds; D012989:Soil Pollutants