Determination of cyclic volatile methylsiloxanes in biota with a purge and trap method.
The three cyclic volatile methylsiloxanes (cVMS), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), are recently identified environmental contaminants. Methods for the trace analysis of these chemicals in environmental matrices are required. A purge and trap method to prepare highly purified sample extracts with a low risk of sample contamination is presented. Without prior homogenization, the sample is heated in water, and the cVMS are purged from the slurry and trapped on an Isolute ENV+ cartridge. They are subsequently eluted with n-hexane and analyzed with GC/MS. The method was tested for eight different matrices including ragworms, muscle tissue from lean and lipid-rich fish, cod liver, and seal blubber. Analyte recoveries were consistent within and between matrices, averaging 79%, 68%, and 56% for D4, D5, and D6, respectively. Good control of blank levels resulted in limits of quantification of 1.5, 0.6, and 0.6 ng/g wet weight. The repeatability was 12% (D5) and 15% (D6) at concentrations 9 and 2 times above the LOQ. The method was applied to analyze cVMS in fish from Swedish lakes, demonstrating that contamination in fish as a result of long-range atmospheric transport is low as compared to contamination from local sources.
Department of Applied Environmental Science (ITM), Stockholm University, SE-106 91 Stockholm, Sweden. amelie.kierkegaard@itm.su.se
Amelie
A
Kierkegaard
Margaretha
M
Adolfsson-Erici
Michael S
MS
McLachlan
D000388:Air; D053000:Analytic Sample Preparation Methods / Q000379:methods*; D000818:Animals; D058448:Biota; D003080:Cold Temperature; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D005399:Fishes; D057230:Limit of Detection; D008099:Liver / Q000737:chemistry; D012833:Siloxanes / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D012997:Solvents / Q000737:chemistry; D014835:Volatilization; D014867:Water / Q000737:chemistry
D004785:Environmental Pollutants; D012833:Siloxanes; D012997:Solvents; D014867:Water