A submicron mesoporous silica for the determination of organosulphur in sea water

Organosulphur compounds were determined in seawater samples by gas chromatography using a pulse flame detection method. The analytical method involved the use of octyl-diol mesoporous silica as a replacement for organic solvents in the extraction and pre-concentration of organosulphur compounds from seawater samples based on the solid phase dispersion extraction technique. The detection limits were in the range 0.6–2 ng S/L, while the repeatability and reproducibility were 7–12% and 13–16% respectively. Relative standard deviations (%) for recovery of n-ethanthiol (n-EtSH), di-n-ethyl sulphide (n-Et₂S) and di-n-ethyl disulphide (n-Et₂S₂) in spiked water samples were in the range 2.2–6.6% (at 0.5 μg/L level). Under the experimental conditions used, quantitative extraction of n-EtSH, n-Et₂S and n-Et₂S₂ was achieved with recoveries ranging from 93% to 99%. The procedure has been successfully applied to organosulphur determination in seawater samples collected from Jeddah beach (West of Saudi Arabia).