Aguilera-Herrador E, Lucena R, Cárdenas S, Valcárcel M. Continuous flow configuration for total hydrocarbons index determination in soils by evaporative light scattering detection.
J Chromatogr A 2007;
1141:302-7. [PMID:
17182047 DOI:
10.1016/j.chroma.2006.12.021]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 11/29/2006] [Accepted: 12/01/2006] [Indexed: 11/28/2022]
Abstract
A continuous flow configuration is proposed for the estimation of the hydrocarbon index in soils using for the first time evaporative light scattering detection (ELSD). The method is based on a membrane-enrichment of the hydrocarbons of interest (C10-C40), which are previously extracted from the soil matrix with a water:hexane mixture using a household microwave oven. The organic supernatant is cleaned-up through silica, evaporated and redissolved in a sodium dodecyl sulphate aqueous solution which is introduced in the loop of an injection valve. The sample, carried by an aqueous stream, passes through a continuous filtration unit fitted with a 1 microm pore size PTFE membrane, where the hydrocarbons are retained while the potential coextracted compounds are wasted. Quantitative elution of the C10-C40 fraction is accomplished by passing an acetone stream through the filter which drives the analytes to the ELSD system for analytical measurement. The detection limit was 1.8 microg ml(-1), the linear range 5-25 microg ml(-1) and the precision 4.3%. The recoveries were between 93 and 97%. The proposed method was also evaluated by attenuated total reflexion-Fourier transform (ATR-FT-IR) analysis of the extracts.
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